IN 



m 







Class XIXW- 

Book JL H& 

Ocpightlf 



COPYRIGHT DEPOStT. 



THE 

ARTIFICIAL FEEDING 

OF 

INFANTS 



THE 

ARTIFICIAL FEEDING 

OF 

INFANTS 



INCLUDING A CRITICAL REVIEW OF THE 

RECENT LITERATURE OF THE 

SUBJECT 



BY 

CHARLES F. JUDSON, M.D. 

PHYSICIAN TO THE MEDICAL DISPENSARY OF THE CHILDREN'S HOSPITAL 
AND 

J. CLAXTON G1TTINGS, M.D. 

ASSISTANT PHYSICIAN TO THE MEDICAL DISPENSARY OF THE CHILDREN'S 
HOSPITAL 




PHILADELPHIA 

J. B. LIPPINCOTT COMPANY 

1902 



THE LIBRARY OF 
CONGRESS, 

t>vo Cowt* Received 

MAY, 31 1902 

Copyright entry 

CLASS <*- XXa No. 

COPY B. 




Copyright, 1902 
By J. B. Lippincott Company 



MINTED BY J. B. LIPPINCOTT COMPANY, PHILADELPHIA, U.S.A. 



J 



PREFACE. 

¥¥ 

The aim of this work is to place before the medical pro- 
fession a thorough and reliable account of the principles and 
methods of artificial feeding in vogue at the present day. 
Much valuable material (not contained in the average text- 
book) has been collected, representing the results of extended 
scientific investigations. The substance of this work has been 
gleaned from the periodical literature, monographs, and text- 
books of the past eight years (1894-1901), so that this treatise 
may justly claim to be an authoritative statement of the views 
of the leading pediatrists and scientists of Europe and America 
on the subject of Artificial Feeding at the present day. Grate- 
ful acknowledgment is made of our indebtedness to the authors 
cited for their readily granted permission to quote from their 
works; especially we thank Professor A. B. Marfan, of Paris, 
Professor Monti, of Vienna, Dr. Cautley, of London, and Mr. 
H. Droop Richmond, chemist of the Aylesbury Dairy Com- 
pany, whose names find frequent mention throughout the 
following pages. 

It is inevitable in a treatise of this character that many 
repetitions should occur and that many conflicting statements 
should be made. Since the purpose of the work is to give 
a clear, impartial statement of the views of each author, de- 
tailed criticisms of their methods of feeding are avoided; but 
it has been the authors' aim to incorporate in the concluding 
chapters (XII., XIII., and XIV.) the guiding principles which 

5 



6 PREFACE. 

form the groundwork of all methods of feeding. An attempt 
has been made on this basis to construct a theory of infant 
feeding which shall be sufficiently broad in its scope to meet 
the widely varying needs of different infants, the cardinal 
principle being kept in mind that each case is a unit, and that 
we must carefully adjust the diet to the requirements of the 
individual infant if we wish to be successful. 

The management of lactation (and wet-nursing) has not 
been considered, since it does not directly concern the purpose 
of this book. 

Professor Henry Leffmann kindly consented to review the 
statements relating to the chemistry of milk and milk products, 
and Dr. David L. Edsall the chapter on Metabolism. 

In conclusion, we desire to thank Dr. Harvey Shoemaker for 
much kind advice, Mr. Walter E. Cuthbert for his practical 
assistance, and our publishers for their courtesy and aid in the 
preparation of the work. 



CONTENTS. 



¥¥ 

CHAPTER PAGE 

I. Historical 9 

II. Mother's Milk 18 

III. Cow's Milk 44 

IV. Digestion 61 

V. Modern Methods of Infant Feeding 94 

VI. Weaning 167 

VII. Care of the Milk 179 

VIII. Bacteriology 196 

IX. Sterilization and Pasteurization 216 

X. Weight and Growth — Metabolism 237 

XI. The Feeding of Premature Infants 270 

XII. Principles of Infant Feeding 275 

XIII. Methods for the Home Modification of Milk 296 

XIV. Practical Rules for Feeding 318 

XV. Artificial Foods 327 

Appendix 335 

Bibliography 345 

Index 355 



THE 

ARTIFICIAL FEEDING 

OF 

INFANTS. 

¥¥ 

CHAP TEE I. 
HISTORICAL. 

A cursory survey of earlier publications treating of the 
artificial feeding of infants shows that the necessity of dilu- 
tion to adapt cow's milk to the infant's powers of digestion 
was recognized as far back as the middle of the eighteenth 
century. In a treatise entitled " On the Raising of Healthy 
Infants/' published by J. P. Frank in 1749, we read that Von 
Swieten, Loseke, and Cosner were the first to recommend di- 
luted cow's milk for infant feeding; they advised to dilute 
from two to five times with water. 7 Frank advocated dilution 
with either plain water, barley-, wheat-, or oatmeal-water. 7 

The use of ass's milk and of animal broths seems to have 
found early recognition. John Armstrong, in " An Account 
of the Diseases most incident to Children," London, 1783, 
recommends that the nursing child should take, in addition 
to the breast, pap or panada made from bread-crumbs boiled 
in water and sweetened with sugar. If the child be artificially 
fed from the start, it should have " cow's milk mixed with its 
victuals as often as possible and now and then a little of it 
alone to drink. Ass's milk will be still better." If the milk 
disagrees, animal broths should be given. To assist teething 
and promote the secretion of the salivary glands, a crust of 

9 



10 THE ARTIFICIAL FEEDING OF INFANTS. 

bread dipped in water or milk should be given to the child to 
suck. 

The next advance in methods of feeding among English 
writers is to be found in John Clarke's " Commentaries on 
the Diseases of Children," London, 1815. This author was 
one of the first to advocate the employment of cream diluted 
with starchy decoctions; he also seems to have used whey as 
a beverage. To quote his own words: "Ass's milk is the 
best substitute for that of the mother — cow's milk is too rich 
and contains too much oil and cheesy matter. The latter is, 
moreover, formed by the gastric juice in the stomach into a 
firm curd, which is not digestible by the stomach of an infant. 
Diluting it with water does not entirely prevent this; there- 
fore, when ass's milk cannot be procured, it is best to mix 
cow's milk previously skimmed with two-thirds or three-fourths 
of its measure of gruel made from pearl-barley, grits, or arrow- 
root. When so mixed it does not become hard in the stomach, 
. . . but forms a thick fluid. As a child advances in age 
the proportions of milk may be gradually increased. Where 
this food does not agree with the child, weak mutton, chicken, 
or beef broth, clear and free from fat, mixed with an equal 
measure of the mucilaginous or farinaceous decoctions above 
mentioned, may be tried. With some children, when no form 
in which cow's milk can be given will agree, the stomach will 
digest farinaceous decoctions mixed with cream. Solid animal 
food should not be given until the child has all the canine teeth, 
and then in small quantities and only once a day. Water 
either plain or with toasted bread infused into it, and rennet 
whey, are the best beverages for children. As soon as a child 
has got any of the teeth called incisors, solid farinaceous mat- 
ter boiled in water, beaten through a sieve and mixed with a 
small quantity of milk, may be employed, and then for the 
first time the child should be fed by hand. When the molars 
or grinding teeth have protruded through the gums, the child 
should live upon farinaceous matter, mixed with milk or weak 



HISTORICAL. 1 1 

broth, but the bread need not be beaten through a sieve, be- 
cause the child has now an apparatus for grinding it." 

The directions given by Dewees for the preparation, hand- 
ling, and administration of an infant's food are very similar 
to those in vogue at the present day. Dewees recognized the 
value of the application of heat to prevent decomposition of 
the milk, but advised against the use of prolonged heat at a 
temperature at or above boiling. We quote from the fourth 
edition of his work on Children's Diseases, Philadelphia, 1832 : 

" Milk should be diluted one-third with water and loaf sugar 
added to make the proportions resemble mother's milk. 

" I. The milk should be pure, not skimmed or watered, and 
used as soon as possible after milking. 

" II. When practicable, use milk from the same cow, to 
avoid variations. 

" III. Mix sugar and water just before giving, to avoid fer- 
mentation. 

" IV. Only the quantity should be prepared that will be 
used. 

"V. Milk should be heated by adding hot water or by a 
sand-bath, not on a range. 

"VI. Milk should be kept in the coolest possible place. 

" VII. It should be rejected if acid. Too much must not 
be given at once. 

" In cool weather, after the fifth month, barley-, rice-, or 
gum-arabic-water may be added to the diet if desired, also a 
small amount of arrowroot, or a small amount of some animal 
juice may be given in conjunction. After the child has its 
molars, the diet should consist principally of milk, to which 
grated cracker, well-baked stale bread, rice flour, or arrowroot 
may be added; occasionally, animal broths may be used, pref- 
erably beef, mutton, or chicken. After the eye- and stomach- 
teeth have erupted, small amounts of roasted meats may be 
added once a day. Stale bread and butter — the latter must be 
of good quality — are permissible at this age. Butter is not 



12 THE ARTIFICIAL FEEDING OF INFANTS. 

only innocent bnt highly useful; the use of potatoes is not 
recommended, except in small quantities and only after the 
ninth month; they should be well mashed with hot milk, but- 
ter, and salt. 

" I. Never put a second supply of milk upon the remains of 
a former, unless a very short interval has elapsed and they are 
of the same making. 

" II. So soon as a child has taken as much as it chooses, or as 
much as may be judged proper for it, let the bottle be emptied 
of any food remaining and immediately cleansed by hot water. 

" III. When well cleansed by the hot water, let it be thrown 
into and kept in a basin of cold water in which there is a little 
soda dissolved. 

" IY. Before using let it be rinsed with clear cold water. 

"V. Let the extremity from which the child is to suck be 
covered with a heifer's teat in preference to anything else. 

"VI. Let not the teat be of too large a size, nor one that 
will permit too rapid a flow of the food, especially for a very 
young infant. 

" Cow's milk contains more cheesy matter, and is on this 
account of more difficult assimilation; hence it is frequently 
thrown up in the form of a hard curd. Only so much milk 
must be taken into the stomach as the infant can assimilate 
and digest in due time ; the latter may be fixed at three to four 
hours. 

"Upon no occasion, when the child is in health, will the 
milk require boiling, for this takes from the milk some of its 
best qualities. In hot weather, it is true, the tendency to 
decomposition is diminished by boiling the milk, but as all the 
advantages which result from this process can be procured 
without its being absolutely boiled, it should never be had 
recourse to. 

" It is every way sufficient for the purpose of preservation 
that the milk be put closely covered over a hot fire and brought 
quickly to the boiling point; so soon as this is perceived, it 



HISTORICAL. 13 

should be removed and cooled as speedily as possible. By this 
plan we prevent in great part the formation of that strong 
pellicle which is always observed on the top of boiled milk, and 
by which the milk is deprived of one of its most valuable 
parts. 

" For a certain period after each meal rest is essential to 
digestion, as exercise is important at other times for the gen- 
eral promotion of health. 

" The preposterous and highly injurious practice of l jolting' 
should be absolutely prohibited. 

" The bottle must not become the plaything of the child. 

" The child should not receive its nourishment while lying ; 
it should be raised. 

"When the child ceases to extract milk from the bottle, 
and this be restored to the child, who again refuses to take it, 
let the child on no account be urged to swallow more than 
nature seems to demand. This also holds good when the child 
is at the breast." 

Carl Gerhardt 59 in 1871 recommended dilutions of cow's 
milk for different ages to be prepared in the following man- 
ner : for the first eight days one part of milk to three parts of 
water, from that time up to three months one to two, from 
four to nine months equal parts of milk and water, and after 
the ninth month pure milk. After the sixth month meat broth 
can be used as a diluent. 

John Forsyth Meigs, of Philadelphia, a renowned pedi- 
atrist in his day, was the originator of a mixture of milk, cream, 
gelatin, and arrowroot-water (see his text-book, second edition, 
1853) which gave very satisfactory results for the feeding both 
of sick and healthy infants. He advised for a child of good 
health under one month from three to four ounces of milk, 
one-half to one ounce of cream, and half a pint of arrowroot- 
water (containing one drachm of arrowroot). For older chil- 
dren the quantity of milk was to be increased to one-half or 
two-thirds of the total mixture, and the cream raised to two 



14 THE ARTIFICIAL FEEDING OF INFANTS. 

ounces. During the seventies he advocated the use of a mixture 
of equal parts of milk, cream, lime-water, and arrowroot-water, 
sweetened with a little sugar. In this preparation the princi- 
ples governing modification of milk for infant feeding are 
correctly outlined, and it is not too much to say that all the 
later advances in method start from this fountain-head. The 
elder Meigs recognized the importance of adding cream to make 
up the deficiency in fat of his mixture, and it was due to his 
incentive that the younger Meigs pursued the question further, 
with the result of determining the proportions of the proteids 
in mother's milk, thus placing the question of dilution on a 
scientific basis. 

The subject of the percentage of proteids in mother's milk 
was a mooted one until recent years. Chemical researches had 
given varying results, the methods employed being generally 
inaccurate. During the fifties and sixties the tendency was to 
accept the figures of Yernois and Becquerel, who had found 
a casein percentage of 3.924. Eegnault, Simon, and Clemm 
obtained similar results, but Henri and Chevalier had found 
an average of 1.52 per cent., l'Heritier 1.3 per cent., and 
Quevenne 1.05 per cent. The latter figures were not, however, 
generally considered reliable, since they were based on a small 
number of cases only ("Milk Analysis and Infant Feeding," 
Meigs). Brunner, as far back as 1873, had published the re- 
sults of his analyses of human milk, which gave him an aver- 
age of from 1.3 to 1.4 per cent, casein (Pfiuger's Archiv 
fur Physiologie, Bd. vii. ) . On empirical grounds Biedert had 
arrived at the conclusion that the proper proportion of cow's 
milk casein in an infant's food was one per cent., and had 
formulated his Cream Mixture accordingly. Biedert's article 
in Virchow's Archiv for 1874 advised the use of a mixture 
of cream diluted four times with water, to which milk-sugar 
was to be added. He concluded from numerous experiments 
on the coagulability and digestibility of human and cow's milk 
that they varied in two important points : " first, in the dif- 



HISTORICAL. 15 

ferent amounts of casein contained; second, in the absolute 
chemical differences of the two sorts of casein." 160 Biedert's 
Cream Mixture contained one per cent, casein, 2.4 per cent, 
fat, and 3.6 per cent, sugar of milk. 

The question of the percentage of casein in mother's milk 
was still unsettled in 1882, when Arthur V. Meigs an- 
nounced the results of his investigations, which determined the 
amount of proteids to be one per cent, (approximately) and 
the sugar seven per cent. These figures were based on analyses 
of the milk of forty-three women, the samples being obtained 
at different times and under varying circumstances. Starting 
from the assumption that cow's milk must be diluted suffi- 
ciently to reduce the casein percentage to that of human milk, 
Meigs devised the following preparation, commonly known as 
"the Meigs Mixture," which, in his opinion, meets the re- 
quirements of infant feeding. 

173 a There must be obtained a quart of good fresh milk ; 
not too rich and not poor, average milk is best ; this is placed 
in a high pitcher or other vessel and is allowed to stand in a 
cool place for three hours. The upper half or pint is then 
poured off, care being taken not to shake the vessel, and this 
upper pint, of weak cream, is to be kept for the use of the 
infant. The other half of the quart, which is skimmed milk, 
may be sent to the kitchen. There must also be made a solu- 
tion of milk-sugar of the proportion of eighteen drachms to 
the pint of water. It is best to weigh the sugar, or to have 
an apothecary prepare a number of packages each containing 
eighteen drachms of milk-sugar. A wide-mouthed pint bottle 
should be provided, into which may be put eighteen drachms 
of milk-sugar and one pint of water. By having a wide- 
mouthed pint bottle there is no need for any other measure, 
and the sugar in bulk is more easily put into such a bottle 
than into an ordinary one with a narrow neck. The sugar- 
water must be kept in a place that is not too hot, nor should 
it be kept in a refrigerator, as great cold precipitates the sugar 



16 THE ARTIFICIAL FEEDING OF INFANTS. 

and heat causes it to ferment. In hot weather the sugar solu- 
tion should be examined from time to time, and if it sours 
must be thrown out and prepared afresh. Having the milk 
and the sugar-water ready, only one other ingredient is re- 
quired, lime-water. 

" When the food is to be used there must be taken of the 
weak cream (the upper pint which was poured off and retained) 
three tablespoonfuls, of the lime-water two table spoonfuls, and 
of the sugar-water three tablespoonfuls. These substances 
together are placed in a feeding-bottle and warmed to the 
degree which may be desirable; the food is then ready for 
use. 

" An infant two days old should take only about half an 
ounce of nourishment at a feeding, and it will take this amount 
seven or eight times each day; if it sleeps naturally, it is not 
possible to feed every two hours, which would make twelve 
feedings per day. The proper quantity, therefore, for a two- 
days-old child is between three and four ounces. 

" The daily amount required will gradually increase, until 
at the end of twenty-one days it will be found that the infant 
is taking about two and a half ounces at a time, and still about 
seven or eight feedings in each day, making a total of from 
seventeen to twenty ounces. When the sixth week has been 
reached, about four ounces will be taken at a time, making a 
total quantity of nearly thirty-two ounces. These estimates 
of the amount of food for infants during the first few weeks 
of life may possibly be a little too high, but they will not be 
found to vary much from what babies should have at that 
period of life. . . . Generally a baby should not be urged to 
take more than it wants, unless it is very indifferent to food 
and takes much less than the quantities above mentioned. 

" After the first six weeks it will be found that there is a 
natural desire for an increased quantity of food, just as there 
was in the earlier period. The amount taken by a healthy 
infant will increase to six or eight ounces at each feeding, 



HISTORICAL. 17 

but generally the number of daily feedings will grow less. A 
very young infant will require to be fed seven or eight times 
a day, but one of from four to six months will only take nour- 
ishment from five to seven times a clay. The quantity taken 
will be found to vary between somewhat less than two pints 
and three pints. The food, therefore, is to be increased in 
amount, but continued always of the same strength until an 
infant is from six to nine months of age." 

Meigs has never been an advocate of sterilization under ordi- 
nary circumstances. " It certainly must alter the milk to be 
cooked, and sterilization is cooking, whether the heat applied 
be of high or only of moderate degree. It seems better and 
more natural to see that the milk is pure and free from all 
contaminations, in the first place, than to purify by steriliza- 
tion a milk which is supposed to be contaminated, and then 
use it to feed babies. The field of usefulness of the process 
of sterilization is probably to be found in cases where it is 
impossible to secure pure milk, but as to using it as a matter 
of general application it is not to be recommended." 

During an experience of fourteen years Meigs has used this 
food with great success. He estimates its composition as fol- 
lows : 

Per cent. 

Water 87.639 

Fat 4.765 

Casein 1.115 

Sugar 6.264 

Salts 0.217 

100.000 



CHAPTER II. 

MOTHER'S MILK. 

Since mother's milk is universally recognized as the stand- 
ard which should be imitated in the artificial feeding of in- 
fants, it will be the object of this chapter to give a succinct 
account of its composition and characteristics. No attempt 
will be made to discuss the physiology or the management of 
lactation, since the purpose of this work is to discuss the 
principles governing the artificial feeding of infants. 

Description. 

Mother's milk is the secretion of the mammary gland, and 
consists of an emulsion of small fat-droplets in which salts, 
sugar, and proteids are held in solution. At the height of 
lactation it is bluish-white and semi-transparent, of sweetish 
taste, odorless, and has a specific gravity of from 1026 to 1036 
(Monti). 

According to Leeds, 166 the color of milk, which may be 
chalky-white, bluish-white, yellowish-white, or yellow, is no 
indication of its composition. A chalky looking specimen may 
be rich in fat and a yellow sample poor in that constituent. 
Mother's milk has rarely a sweet taste; more often it is saline 
and of a somewhat disagreeable animal odor. Its consistence 
is much thinner and more watery than cow's milk. 

Specific Gravity. 

Adriance 1030 average 

Bichmond 1030-1031 average 

Holt 1029-1032 

Monti 1030-1034 

18 



MOTHER'S MILK. 19 

Variations. 

Johannessen 1025-1036 

Leeds 1026-1035.3 

Adriance 1017-1036 

An increase of the fat lowers the specific gravity, a decrease 
raises it. The proteids and other solids have a reverse effect, 
while the salts are too insignificant to affect it one way or 
the other. As the sngar varies so slightly, it may be considered 
that, for clinical purposes, the specific gravity is modified solely 
by the fat and the proteids (Adeian"ce 69 ). 

In Monti's experience, " breast-milk which has a specific 
gravity of 1030 to 1035 and at the same time a fat content 
of three to five per cent., — that is, in which the height of 
the specific gravity corresponds with that of the fat per- 
centage, — and in which only slight changes in these factors 
occur during nursing, may be considered a good one/' Low 
fat averages (from one to two per cent.) and low specific 
gravity (1026 to 1029) are found associated usually in the 
milk of anaemic, poorly nourished women. In those cases 
in which the woman's milk shows a high specific gravity and 
a low or subnormal fat content, the infants do not thrive, and 
such a milk must be considered to possess less nutritive value. 
The only sure test, however, is the child's weight. 

Estimation of the Proteids. {Holt's Method.) 

" In estimating the proteids certain suppositions must and 
can be fairly accepted. 

" I. Supposing the proteids to remain unaltered ; if the per- 
centage of fat be low, the specific gravity will be high; but 
if high, the specific gravity will be low. 

" II. Supposing the fat to remain unaltered ; if the percent- 
age of the proteids be high, the specific gravity will be high; 
but if the percentage of the proteids be low, the specific gravity 
will be low. If, therefore, the fat and the specific gravity be 



20 THE ARTIFICIAL FEEDING OF INFANTS. 

known, any considerable variation in the proteids may be 
estimated by the following data: 

Data. Conclusion. 

Percentage of cream. Specific gravity. Amount of proteids. 

High,— e.g., from 8-10 High, 1033-1034 High percentage 

Low, — e.g., from 3-4 High, 1033-1034 Nearly normal 

High Low, 1027-1030 Normal 

Low Low, 1027-1030 Deficient" 

Holt asserts that the conclusions drawn from this mode of 
examination are as exact as those obtained by the ordinary 
examinations of urine. 

H. Droop Eichmond considers that " Holt's method is based 
on a fallacy/' and that the results obtained with it are, on the 
whole, unsatisfactory. 

Eeactiois t . — Authorities are practically agreed that the re- 
action of normal mother's milk is uniformly alkaline. 

Colostrum. 

Marfan. 105 Colostrum is secreted by the mammary gland 
towards the end of pregnancy. It is a grayish-yellow fluid, 
of serous consistence and slightly turbid, containing streaks 
of deep yellow. Its reaction is alkaline and its density from 
1046 to 1065. 

Microscopically, there are found: (a) fat-droplets, some 
like those of normal milk and others smaller, poorly formed, 
and often agglutinated, which denote the imperfection of the 
milk secretion; (b) leucocytes, some of which contain fatty 
detritus; (c) colostrum corpuscles, large spherical bodies, 
consisting of fatty detritus surrounded by a membranous en- 
velope, and often showing amoeboid movements. 

The first day after birth the secretion of the mammary gland 
contains many colostrum corpuscles and fat-globules of un- 
equal size. With the appearance of milk on the third day the 



MOTHER'S MILK. 



21 



colostrum bodies become less numerous, but the secretion still 
has a yellowish color. On the sixth day there are many fat- 
globules which are less unequal in size, and the colostrum cor- 
puscles diminish further in number. After the fifteenth day, 
as a rule, we find no colostrum corpuscles; the milk is per- 
fectly white and normal in appearance. The fat-giobules tend 
to become more nearly equal in size, but vary in different sub- 
jects, however, during lactation. 

Monti " states that the colostrum corpuscles are usually 
present for about one week after labor, and that any consider- 
able quantity at a later period denotes either disease of the 
mother or pregnancy. Jacobi 76 calls attention to the fact that 
excessive proteids are apt to cause gastro-intestinal symptoms 
during the colostrum period, particularly after premature con- 
finement. 

Adeiance 4 considers that the colostrum period covers the 
first two weeks of life. During this time we not infrequently 
find the fat percentage either very low or very high. The 
sugar content is lower than at any other time, but rises rapidly, 
ranging from 5.80 per cent, on the second day to 6.63 per 
cent, on the fourteenth day. The proteids pursue a contrary 
course, falling from 2.77 per cent, on the second day to 1.70 
per cent, on the fourteenth day. The ash, like the proteids, 
is higher at this period than at any other. Examples of colos- 
trum milk are cited to show the changes during the first part 
of lactation. 





Mother- 


—TWENTY 


Mother- 


-NINETEEN 


Mother- 


—TWENTY- 




years. 


years. 


three 


YEARS. 




Three 
days. 


Six 
days. 


Two 
days. 


Ten 
days. 


Six 
days. 


One month, 

seventeen 

da vs. 




Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


Fat 


... 4.52 


2.80 


3.77 


2.64 


4.30 


4.08 


Sugar 


... 5.86 


6.83 


5.39 


6.62 


5.38 


6.91 


Proteids . . . 


... 2.37 


2.13 


3.31 


1.70 


2.79 


1.44 


Salts 


... 0.26 


0.25 


0.27 


0.23 


0.23 


0.19 



22 THE ARTIFICIAL FEEDING OF INFANTS. 

Woodward, 249 in the Journal of Experimental Medicine, 
March, 1897, reports the results of the examination of six 
cases of colostrum milk at the Pepper Clinical Laboratory. 
He found the color yellow, the reaction alkaline, and the specific 
gravity from 1024 to 1034, depending on the amount of fat 
present, which varied from two to 5.3 per cent. The proteids 
ranged from 1.64 to 2.22 per cent, and the ash from 0.14 to 
0.42 per cent., while the total solids varied from 10.18 to 13.65 
per cent. The lactose (calculated) percentage was from 5.6 
to 7.4. An average colostrum milk contains four per cent, of 
fat, 1.9 per cent, of proteids, 6.5 per cent, of lactose, and 0.2 
per cent, of ash, making the total solids 12.5 per cent, and 
water 87.5 per cent. 

Microscopical examination of the corpuscles by A. E. Taylor 
showed a small, irregular, but much degenerated nucleus. 
The protoplasm is more or less filled with large and small 
granules, only a few of which are stained by osmic acid. These 
granules will not stain with acid, basic, and neutral dyes; 
they show the characteristics of proteids in their reactions. 
The few granules which are stained with osmic acid are probably 
fatty. The most marked feature is the constant and excessive 
degeneration. 

Composition of Mother's Milk. 

Before discussing the elements which constitute mother's milk, 
it will be well to quote the average percentages of the different 
ingredients as they are given in some of the leading text-books. 

In glancing over the tables, it at once appears that there 
are greater variations in the proteid content than in that of 
the other ingredients. Monti's maximum of five per cent, pro- 
teids must be considered an abnormally high figure. 

Although variations in the fat and proteid content may 
occur at any period of lactation, it will be shown in the fol- 
lowing pages that the composition of mother's milk tends to 
approximate a certain average after lactation has become well 
established. 



MOTHER'S MILK. 



23 





Baginsky.» 


Max. 


Monti. 
Min. 


19 

Aver. 


H01T.69 


ROTCH."9 




Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


Water . . . 


87-88.5 


90.1 


84.9 


88.6 


85.5-89.82 


87-88 


Solids 


11.5 
1.7 


16.5 
5.0 


10.0 
1.2 


11.0 
2.7 




12-13 


Proteids . . 


1-2.75 


1-2 


Casein. . . . 


1.2 

0.5 

3.8-4.07 


4.0 


2.0 


3.0 






Albumin . 






Fat 


3-5 


3-4 


Lactose . . 


6-7.03 


7.0 


3.0 


5.0 


6-7 


6-7 


Ash 


0.2-0.21 


0.2 


0.1 


0.20 


0.18-0.25 


0.1-0.2 



Baginsky's table seems to be averaged from the figures of Lehman n and 
Hoffmann. 

Monti's table is drawn from the figures of Pfeiffer, Konig, Hoffmann, 
and Johannessen. 

Holt's table is based on the analyses of Pfeiffer, Konig, Leeds, Harring- 
ton, and others. 

Eotch's table represents the analyses of Kdnig, Forster, Meigs, Harring- 
ton, and others. 

Proteids. 

The chief proteids in mother's milk are casein, lactalbumin, 
and lacto-globulin. That lactalbumin is present in mother's 
milk is maintained by Lehmann, Schlossmann, Bendix, Ba- 
ginsky, Monti, Holt, Eotch, and others, whereas Pfeiffer and 
Duclaux deny its existence. 

The proteids of mother's milk are partly in solution and 
partly in suspension (Eotch). .The casein is in suspension by 
virtue of the presence of calcium phosphate, with which it is 
probably combined, while the lactalbumin is in solution and 
resembles serum-albumin (Holt, Monti). .Schlossmann states 
that casein contains phosphorus, and that lactalbumin contains 
sulphur in soluble form. In his latest series of analyses Schloss- 
mann estimates the average amount of total proteids in mother's 
milk at 1.56 per cent. In an earlier series of analyses he found 
that of the total proteids sixty-three per cent, were represented 
by casein and thirty-seven per cent, by lactalbumin. According 



24 THE ARTIFICIAL FEEDING OF INFANTS. 

to Lehmann and Bendix, the total proteids equal 1.7 per cent., 
and the ratio of casein to albumin is as 1.2 to 0.5 per cent. 
Camerer asserts that older milk contains relatively more casein 
than albumin, and Monti confirms this statement. In the 
latter's opinion, during the first months of life the breast-milk 
is characterized by a high content in lactalbumin as compared 
with casein. With the advance of lactation the amount of 
lactalbumin diminishes very decidedly, so that in the last 
months the casein predominates. Schlossmann considers that 
this large proportion of soluble albumin is of great help to 
digestion, since the infant obtains a considerable part of the 
nitrogen he requires in & form in which it can be directly 
absorbed, whereas casein has to undergo complicated changes 
before it is ready for absorption. The presence of lactalbumin 
causes precipitation of the casein in much finer flakes, as does 
also that of the finely emulsified fat. On the other hand, 
Baginsky doubts whether a marked difference exists between 
casein and lactalbumin in regard to their digestibility and 
ease of absorption, since there is ground for the assumption 
that mother's milk is absorbed in toto by the lacteals, — that is, 
without special preparation. (It seems questionable whether 
the casein of mother's milk can be absorbed as such. — Editors.) 
Monti says that during the first two months of lactation 
normal milk has a proteid content of from two to two and a 
half per cent. (Percentages above two after the first three 
or four weeks of lactation may be considered above the aver- 
age. — Editors.) If the ratio of casein to albumin is altered, 
especially if too little fat (less than three per cent.) is present, 
such a milk will disagree. A proteid content below two per 
cent., or even down to one per cent., may agree with the child 
at this period, but the latter proportion is too low for proper 
thriving. Over three per cent, is abnormal and will disagree 
at any period of lactation. After the second month from one 
to one and a half per cent, of proteids is present, and such 
a proportion will suffice for the needs of the infant if the 



MOTHER'S MILK. 25 

fat percentage is normal. Below one per cent, of proteids, 
however, is always abnormal, and, even if the fat is normal 
in quantity, children will not thrive on such a milk. 

Analyses of Proteids in Human Milk. 

In 1895 Johannessen" 75 published the results of his investi- 
gations of mother's milk, based on one hundred and fifty sam- 
ples from twenty-five healthy women; they were between 
twenty and forty-six years of age, most of them living in the 
city and in needy circumstances. The analyses were made 
daily for months together in all but a few of the cases. Fifty 
cubic centimetres were drawn from each breast directly be- 
fore and directly after nursing. Using the Kjeldahl method 
and the Hammarsten-Sebelien coefficient (6.37), he found that 
the total proteid content averaged 1.1 per cent. In ten ex- 
ceptions it rose to 2.6 and 2.8 per cent. For the first six 
months the proteid average was 1.19 per cent., for the next 
six months 0.99 per cent,, and after the first year 0.90 per 
cent. The difference between the nitrogen present in the form 
of casein, albumin, and globulin and the total nitrogen 
amounted to 0.025 per cent, nitrogen. This must be consid- 
ered to represent extractives. 

Heubner 169 gives, as the average proteid content after the 
first week, from 1.02 to 1.2 per cent., based on the analyses 
of Johannessen, Forster, F. E. Hoffmann, Camerer and Sold- 
ner, Munk, Finkelstein, Hirschfeld, and others. The results 
of Adriance's analyses 4 gave a proteid percentage of 1.95 up 
to the third week; from that time to the fifteenth month the 
proteid average was 1.11 per cent. 

Meigs's 9S analyses of mother's milk, which included samples 
from forty women, gave a proteid percentage of 1.05. His 
samples were obtained at varying intervals after nursing. Only a 
small proportion represented the milk of individual cases, the 
remainder being the mixed milk of a large number of women. 

Biedert 7 states that woman's milk has a proteid content, 



26 



THE ARTIFICIAL FEEDING OF INFANTS. 



reckoned as nitrogen, of from 0.85 to 1.72 per cent. ; reckoned 
as proteid pins undetermined remnant, of from 1.11 to 2.65 
per cent. ; whereas the proteids of cow's milk, reckoned as nitro- 
gen, may be pnt at from 2.8 to 3.3 per cent., and, reckoned as 
total proteid constituents, at from 3.08 to 3.44 per cent. The 
composition of each mother's milk has individual characteris- 
tics, especially as to its nitrogenous and fat content; hence it is 
absurd to regard the average of mother's milk as a model, and 
unjust not to set great weight on the quantitative relations. 

For purposes of comparison let us examine Pfeiffer's " Ta- 
ble of Human Milk Constituents at All Periods of Lactation, 
including Two Analyses of Colostrum" (one hundred analy- 
ses in all). 118 



Proteids 

estimated as 

casein. 

Per cent. 

First month (including colostrum) 2.9 

Second month 2.0 

Third month 1.9 

Fourth month 1.7 

Fifth month 1.4 

Sixth month 1.5 

Seventh month 1.5 

Eighth month 1.6 

Ninth month 1.5 

Tenth month 1.7 

Eleventh month 1.4 

Twelfth month 1.7 

Thirteenth month 1.6 



Fat. 



Sugar. 



Salts. 



Per cent. 


Per cent. 


Per cent. 


2.7 


5.7 


0.23 


3.3 


6.3 


0.18 


2.7 


6.4 


0.18 


3.9 


6.6 


0.15 


3.6 


7.3 


0.19 


2.7 


6.8 


0.23 


3.2 


6.8 


0.17 


3.3 


6.3 


0.15 


2.4 


6.6 


0.16 


4.2 


6.2 


0.14 


3.5 


6.6 


0.14 


5.3 


6.0 


0.16 


2.9 


6.6 


0.15 



Pfeiffer's analyses show that mother's milk contains in the 
first days after birth a high percentage of proteids and salts 
and a low fat and sugar content. During the progress of 
lactation the proportions of proteids and salts gradually de- 
crease while the sugar increases; the fats vary constantly. 



MOTHER'S MILK. 27 

Schlossmann, Adriance, and Richmond confirm the latter 
statement. Konig's table " of the average composition of 
mother's milk, based on two hundred analyses, ma}' also be 
cited, although it cannot be considered, in the light of more 
recent investigations, to represent the correct proportions of 
casein to albumin. The percentage of salts given (0.31) is 
abnormally high. 

Per cent. 

( Casein 1.03 ) 

Proteids.... \ I 2.29 

I Albumin 1.26 j 

Fat 3.78 

Sugar 6.21 

Salts 0.31 

Water 87.41 

Solids 12.59 

Magnus Blauberg. 13 In 1894 the results of Lehmann's in- 
vestigations were published by Hempel. 167 This author found 
the average composition of woman's milk to be: casein 1.2 
per cent., albumin 0.5 per cent., fat 3.8 per cent., milk-sugar 
six per cent., ash 0.2 per cent., water 88.5 per cent. Lehmann 
found casein to exist as a double salt of calcium casein with 
lime phosphate. Cow's milk casein contained 6.6 per cent, 
calcium phosphate and 0.723 per cent, sulphur, while mother's 
milk casein contained 1.09 per cent, sulphur and only 3.2 
per cent, calcium phosphate; hence he concludes that the two 
caseins are not identical. 

The proteid averages of Konig and Pfeiffer were considered 
the standard until 1894, when Heubner, in the Congress of 
Hygiene at Pesth, announced the results of Professor Hoff- 
mann's (Leipsic) analyses. Hoffmann obtained a large num- 
ber of samples from the same women, and his investigations 
covered a long period. He concluded that after the third week 
from delivery, milk varies little in its composition from month 
to month, and gives the following average: proteids 1.03, fat 
4.07, sugar 7.03, and ash 0.21 per cent. 



28 



THE ARTIFICIAL FEEDING OF INFANTS. 



Soldner/ at Camerer's instigation, determined to subject 
previous methods of analysis to a rigid test. He found by 
a series of parallel experiments that the Kjeldahl method for 
estimating nitrogen was perfectly applicable to milk, and gave 
reliable results (agreeing in this with Munk, in opposition 
to Salkowsky, who states that the Kjeldahl method gives too 
low figures for casein). The analyses of mother's milk by 
Soldner were based on samples of the breast-milk taken 
throughout the day; the breasts were evacuated as completely 
as possible and the infants nursed during the night. 



Proteid valves (Kjeldahl method) 



Time after birth. N X 6.25 

Per cent. 

Colostrum, early .... 5.8 

Colostrum, late 3.17 

Fifth and sixth days 2.04 

Eighth and ninth days .... 1.54 

Ninth day 1.47 

Ninth and eleventh days . . 1.74 
Fourth, fifth, and eleventh 

days 1.69 

Eleventh day 1.74 

Twentieth and twenty-first 

days 1.36 

Twenty-ninth and thirtieth 

days 1.13 

Seventy-fourth day 0.95 

One hundred and thirteenth 

day 0.95 

Two hundred and twenty- 
ninth day 0.88 



According 
to Munk. 

Per cent. 
5.35 

2.90 

1.81 

1.42 

1.40 

1.61 

1.56 
1.61 

1.11 

1.04 

0.88 

0.88 
0.81 



Proteid plus 
unknown 

extracti ves. 

Per cent. 

7.34 

4.26 

2.66 

2.42 

2.20 

2.03 



2.27 
2.55 

1.61 

1.39 

0.86 

0.94 
0.82 



Unknown 
extrac- 
tives. 

Per cent. 
1.99 

1.33 

0.85 
1.00 
0.80 
0.42 

0.71 
0.94 

0.50 

2 0.35 
£ 0.02 



0.06 



0.01 



Camerer and Soldner conclude from this work that the 
commonly accepted values for proteids are too high. They 



MOTHER'S MILK. 29 

emphasize the high percentage of extractives during the first 
three weeks of life. Such substances are only sparingly found in 
cow's milk, except in colostrum ; among them are traces of urea, 
hypoxanthin, creatinin, potassium sulphocyanate, and lecithin. 

Camerer and Soldner give this average for mother's milk 
at the middle of the second week: sugar 6.5 per cent., fat 
3.28 per cent., ash 0.27 per cent., proteids (according to Munk) 
1.52 per cent., citric acid 0.05 per cent., unknown extractives 
0.78 per cent.; total solids 12.40 per cent. The number of 
samples analyzed is not sufficiently large to establish an aver- 
age for the whole period of lactation. 

Caeter and Eichmond. 39 The table drawn up by these 
authors represents the average of analyses of ninety-four sam- 
ples of human milk, taken almost entirely from women in the 
lying-in department of the Birmingham Workhouse Infirmary. 
With seven exceptions, all the samples were obtained at some 
time within the first month after delivery. In the majority 
of the cases two samples were taken, one before and one after 
suckling; the quantity drawn off is not stated. Most of the 
mothers were healthy and most of the children thrived. 

For the purposes of analysis the Eitthausen method, slightly 
modified, was used. The results of the work may be consid- 
ered to establish an average for the first three weeks after 
birth, since seventy-six out of the ninety-four samples derive 
from this period of lactation. Only four separate breast- 
milks were examined during the fourth week, but three during 
the second month, three during the third month, and one at 
nine and a half months. 

Per cent. 
Water 88.04 

Fat 3.07 

Sugar 6. 59 

Proteids 1.97 

Salts 0.26 

Specific gravity 1031.3 



30 THE ARTIFICIAL FEEDING OF INFANTS. 

The proteid average during the first six days of life was 
2.25 per cent., for the first two weeks 2.05 per cent., and during 
the fourth week 1.72 per cent.; after that time it showed a 
gradual diminution throughout lactation. The same diminu- 
tion was noticed in the ash, — from 0.30 per cent, in the first 
week to 0.26 per cent, in the second week, 0.22 per cent, in 
the third and fourth weeks, and 0.21 per cent, after one month. 
The sugar percentage showed a tendency to increase with the 
progress of lactation. 

The greatest variations were observed in the fat content, 
the next highest in the proteid percentage, and the least in 
the sugar. 

Leeds, 166 on the basis of eighty analyses of human milk, 
using the Gerber-Eitthausen method, asserts that the proteid 
average in breast-milk is about two per cent. He considers 
that the proteids are the most variable constituent in human 
milk, the fat the next most variable, and the sugar the least 
variable. Each sample was taken from both breasts (the 
quantity obtained not stated), and twenty-six out of sixty-eight 
samples were taken from two to three hours after nursing, 
the remainder at intervals varying from five minutes to five 
hours after the child had nursed. Of the total number of 
analyses, forty-one cover the first month of lactation, six 
samples were examined during the second and third months 
respectively, three during the fourth and fifth months, and 
four during the sixth month and period following. This 
number of analyses is hardly large enough to establish an 
average for any period of lactation except the first month; 
we may, however, accept Leeds's proteid average of two per 
cent, as a reliable estimate for the first four weeks of life. 
Leeds found that the proteid content of human milk was 
highest at the beginning (over two per cent.) and became 
less with the progress of lactation; the sugar percentage was 
lowest in the colostrum period, but soon rose and remained 
pretty constant. The fat content is high in the colostrum 



MOTHER'S MILK. 31 

period, but falls after the tenth day; the salts are slightly in 
excess during the first ten days, but vary little during the 
remainder of lactation. 

In January, 1897, John and Vanderpoel Adriance 4 pub- 
lished the results of their analyses of the breast-milk of one 
hundred and twenty cases. All the mothers were healthy and 
of an average age of twenty-five years; sixty-five were primi- 
parse and fifty-five multipara?. The breasts were not entirely 
evacuated for each analysis, but the sample was taken after 
the child had nursed for two minutes. The results of these 
analyses show wide variations in the fat content at different 
periods of lactation, a gradual and steady increase in the sugar 
percentage, and a gradual decrease in the percentages of pro- 
teids and salts. The Kjeldahl method was used. 

Adriance computed that the average specific gravity during 
lactation was 1030, the average fat percentage 3.83, the aver- 
age total solids 12.20, and the average amount of water present 
87.80 (up to the eighth month). He found variations at dif- 
ferent periods of lactation, shown in the accompanying table. 

Carbohydrates. Proteids. Ash. 

Per cent. Per cent. Per cent. 

Second to fourteenth day 5.80-6.63 2.77-1.70 0.27-0.20 

One month 6.68 1.58 0.19 

Three months 6.72 1.44 0.18 

Six months 6.78 1.25 0.16 

Nine months 6.84 1.04 0.16 

Twelvemonths 6.90 0.83 0.15 

Fifteen months 6.96 0.63 0.14 

Schlossmann, 241 in the Archiv fur Kinderheilkunde, Bd. 
xxx., 1900, emphasizes the importance of allowing a sufficient 
interval of time to elapse after the last nursing before obtain- 
ing the sample to be investigated; also the necessity of get- 
ting, for accurate results, as nearly as possible the same quan- 
tity of milk which the infant would have taken from the breast. 



32 



THE ARTIFICIAL FEEDING OF INFANTS. 



The following table represents the results of two hundred and 
eighteen analyses of mother's milk at different periods of lacta- 
tion. The Kjeldahl method was used. The proportion of solu- 
ble albumin to casein was not considered. 



No. of 

cases 

analyzed. 


No. of days 
after birth. 


Fat per 
cent. 


Nitrogen 
per cent. 


N X 6.25 

per cent. 

= proteids. 


Sugar 
per 
cent. 


Calories 
per litre. 


6 


9-10 


4.23 


0.29 


1.81 


6.92 


744 


25 


11-20 


4.63 


0.29 


1.81 


6.89 


780 


41 


21-30 


4.53 


0.31 


1.94 


6.77 


772 


21 


31-40 


5.00 


0.24 


1.50 


6.97 


805 


13 


41-50 


5.41 


0.28 


1.75 


6.80 


847 


24 


51-60 


4.62 


0.25 


1.56 


7.28 


785 


10 


61-70 


4.69 


0.23 


1.44 


6.94 


773 


19 


71-100 


5.39 


0.20 


1.25 


6.77 


823 


25 


101-140 


5.10 


0.20 


1.25 


6.94 


803 


15 


141-200 


4.02 (4.74) 


0.217 


1.29 


6.89 


702(769) 


19 


over 200 


5.55 


0.21 


1.31 


7.33 


863 


218 















The average values in mother's milk during the first seven 
months of lactation are as follows: proteids 1.56 per cent., 
fat 4.83 per cent., sugar 6.95 per cent., nitrogen 0.25 per cent., 
calories per litre, 782. 

The results of these analyses show that : 

I. The proteid percentage in mother's milk is very high 
in the first weeks after birth, diminishing after the thirtieth 
day. From the sixtieth day we observe a more decided and 
rapid fall in the proteid content. It is remarkable how uni- 
form the composition of the milk remains after the seventieth 
day. 

II. The variations in the fat content are much less regular. 
We see the fact again demonstrated that in mother's milk 
the infant obtains a food decidedly richer in fat than is present 
in any kind of artificial food. The fat of mother's milk is 



MOTHER'S MILK. 33 

usually well digested by the infant, even when it is excessive in 
amount. 

III. There is no regularity in the variations in the sugar 
content. We find in the high fat and sugar percentage the 
characteristic prevalence in mother's milk of the non-nitroge- 
nous over the nitrogenous substances. 

IV. In such cases as were observed over a long period of 
time the composition of the milk approximated very closely 
to the average figures given. A low proteid percentage was 
constantly observed in the later months. Schlossmann found 
that the amount of milk secreted by a strong, healthy mother 
was rather in excess of that generally accepted. In a series of 
daily estimations, carried out for long periods of time, the 
quantity secreted varied from one thousand cubic centimetres 
to sixteen hundred cubic centimetres daily. Schlossmann 
thinks that it is more common for the nursing child to get 
too much than too little, since many women have a super- 
abundance of milk. In cases in which the flow is very easy 
and rapid, the child may take in a few moments enough to 
fill the stomach. 

Eotch. 119 " Eeasoning from the strong analogy which must 
exist between human milk and cow's milk, and being aware 
of the great variations which occur in the latter, we may 
assume that human milk is liable to vary considerably in its 
composition with different milkings." Our present knowledge 
of human milk is not sufficiently exact for the formula- 
tion of a table to show the composition of woman's milk at 
different periods of her lactation. " We must also understand 
that human milk of normal quality and proving to be equally 
nutritious to the special infants fed on it may vary considerably 
in the percentages of all its elements and in the combinations 
of these percentages. This fact is well illustrated in the fol- 
lowing table, showing the analyses of fourteen specimens of 
human milk, all differing in the combinations of their different 
elements. 

3 



34 



THE ARTIFICIAL FEEDING OF INFANTS. 



Human Breast-Milk Analyses. 

(Mothers healthy and infants all digesting well and gaining in weight.) 

I. II. III. IV. V. VI. VII. 

Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. 

Fat 5.16 4.88 4.84 4.37 4.11 3.82 3.80 

Lactose 5.68 6.20 6.10 6.30 5.90 5.70 6.15 

Proteids.... 4.14 3.71 4.17 3.27 3.71 1.08 3.53 

Ash 0.17 0.19 0.19 0.16 0.21 0.20 0.20 

Total solids. 15.15 14.98 15.30 14.10 13.93 10.80 13.68 

Water 84.85 85.02 84.70 85.90 86.07 89.20 86.32 

100.00 100.00 100.00 100.00 100.00 100.00 100.00 

Till. IX. X. XI. XII. XIII. XIV. 

Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. 

Fat 3.76 3.30 3.16 2.96 2.36 2.09 2.02 

Lactose 6.95 7.30 7.20 5.78 7.10 6.70 6.55 

Proteids.... 2.04 3.07 1.65 1.91 2.20 1.38 2.12 

Ash 0.14 0.12 0.21 0.12 0.16 0.15 0.15 

Total solids. 12.89 13.79 12.22 10.77 11.82 10.32 10.84 

Water 87.11 86.21 87.78 89.23 88.18 89.68 89.16 

100.00 100.00 100.00 100.00 100.00 100.00 100.00 



" In a number of these cases, when one of the infants who 
was doing well on its own mother's milk was fed with one of 
the other combinations, it soon became sick, and had to be 
changed back to the one adapted to its digestion. Human 
milk may, then, be considered to represent not an especial food 
but a combination of foods, and its fat, sugar, proteids, and 
ash to represent these different foods. In other words, we find 
by experience that the digestive capabilities of infants differ 
just as do those of adults, and that nature provides a number 
of varieties of good human milk adapted to the varying idiosyn- 
crasies of infants." 



MOTHER'S MILK. 35 

Variations in the proteid content of mother's milk may 
occur exceptionally, as follows : 

From 0.6 -2.8 per cent ( Johannessen 75 ). 

From 0. 7 -4. 5 per cent ( Holt 69 ) . 

From 0.85-4.86 per cent (Leeds 166 ). 

From 0. 57-4. 25 per cent ( Konig 119 ) . 

From 1.10-3.62 per cent (Twenty-nine analyses of the Col- 
lege of Physicians and Surgeons, 
New York, cited by Kotch 119 ). 

Fat. 

Monti." Fat as fonnd in mother's milk consists of spherical 
bodies which refract powerfully. They are surrounded, by 
molecular attraction, by a layer of casein which prevents their 
agglutination. The earlier view that they were surrounded 
by an albuminous envelope has been controverted by more 
recent investigators, especially Quincke. According to Woll, 
each cubic centimetre of milk contains from 1,030,000 to 
5,750,000 fat-droplets. Their size varies from 0.001 to 0.004 
millimetres (Fleischmann), and from 0.0024 to 0.0046 milli- 
metres (Woll). 

In general we can distinguish three forms of fat-globules: 
(1) The very large. (2) The medium-sized, which generally 
constitute the chief part of a good milk. (3) Punctiform 
or finely granular. 

On the basis of numerous personal investigations which cor- 
respond with the generally accepted figures, Monti finds that 
the normal fat content of mother's milk varies from two and 
a half to four per cent. Griarre and Biagini, from one hundred 
and forty-nine cases, obtained similar results. Below two per 
cent, and above five per cent, are abnormal. In the milk of 
anaemic and weakly women we often find a fat content of from 
one to one and a half per cent., and in such cases finely granular 
(Class III.) fat-droplets predominate. 



36 THE ARTIFICIAL FEEDING OF INFANTS. 

The fats consist of butyric, caproic, caprylic, myristic, pal- 
mitic, stearic, and oleic acids. According to Kuppel, mother's 
milk is comparatively poor in volatile acids : of the non-vola- 
tile, oleic acid forms one-half; palmitic and myristic are in 
excess over stearic acid.* 

Milk containing very large fat-droplets (Class I.) is apt 
to be very rich in fat (Fleischmann). These may be found in 
excess in the secretion of older women and of those who have 
nursed for a long period, also during menstruation and febrile 
disturbances. In watery milk, poor in fat, there may be a 
predominance of small corpuscles (Class III.). 

The percentage of fat in mother's milk is subject to wide 
and constant variations throughout lactation. The average 
content is variously stated: 

Per cent. 

Mendez de Leon (after the third week) 4.14 

Hoffmann (after the second week) 4.00 

Kichmond (for the whole period of lactation) 3.07 

Pfeiffer (for the whole period of lactation) 3.11 

Johannessen ... .(for the whole period of lactation) 3.21 

Lehmann (for the whole period of lactation) 3.80 

Adriance (for the whole period of lactation) 3.83 

Leeds (for the whole period of lactation) 4.13 

Schlossmann. . . .(for the whole period of lactation) 4.83 

Variations in the fat content of mother's milk have been 
given as follows: 

u Per cent. 

Adriance 1.31-7.61 

Johannessen 0.63-6.65 

Holt 1.12-6.89 

Chemical Laboratory of College of Physicians 

and Surgeons, New York 1.12-5.02 

Konig 1.71-7.60 

Leeds 2. 11-6.89 

* For original, see E. Laves, Zeitschrift fur Physiolog. Chem., Bd. 
xix., and W. G. Ruppel, Zeitschrift fur Biologie, Bd. xxxi. 



MOTHER'S MILK. 37 

Richmond found that the composition of the fat in the early 
part of lactation was different from that towards the close 
of this period. This was seen by studying the volatile fatty 
acids. Where the secretion of milk is deficient, the fat may 
vary from one per cent, before nursing to four per cent, after 
nursing. 

Sugar. 

The percentage of sugar may fairly be stated to average 
from six to seven. Adriance emphasizes the steady slight in- 
crease in the sugar percentage during lactation, from 5.80 on 
the second day to 6.96 at the fifteenth month. Johannessen's 
average of 4.67 per cent, throughout lactation seems to be 
decidedly subnormal, while Meigs's figure of 7.40 per cent, 
exceeds the average. 

Per cent. 

Pfeiffer 6.3 

Leeds 6.93 

Johannessen 4.67 

Bichmond 6. 59 

Lehmann 6.0 

Meigs 7.4 

Schlossmann 6.95 

Adriance 6. 56 

Salts. 

The majority of authors state that the average percentage 
of salts in mother's milk is 0.20. The proportion diminishes 
during lactation, according to Adriance, from 0.27 on the 
second day to 0.14 at the fifteenth month. 

Abnormal variations may occur: from 0.13 to 0.37 per cent. 
(Leeds). Pfeiffer found a minimum of 0.09 per cent.; Eich- 
mond a maximum of 0.50 per cent. Among the most reliable 
analyses of the salts in human milk are those made for Eotch 
in 1893 by Harrington and Kinnieutt. Six quarts of milk 
were analyzed with these results : 



38 THE ARTIFICIAL FEEDING OF INFANTS. 

Per cent. 

Calcium phosphate 23.87 

Calcium silicate 1.27 

Calcium sulphate 2.25 

Calcium carbonate 2.85 

Magnesium carbonate ... 3.77 

Potassium carbonate 23.47 

Potassium sulphate 8.33 

Potassium chloride 12.05 

Sodium chloride 21.77 

Iron oxide and alumina 0.37 

100.00 

This represents the form in which salts probably exist in milk. 

A portion of the lime is united to the casein; the rest is 
combined with phosphoric acid as a mixture of di- and tri- 
calcium phosphates, which are kept soluble and held in sus- 
pension by the casein. 

The phosphorus in woman's milk consists mainly of casein- 
phosphorus, nucleon, and lecithin; it is nearly all held in 
organic combination, whereas in cow's milk less than half 
of the phosphorus is in organic combination. Nucleon is the 
richest in phosphorus of the organic compounds in milk; Witt- 
maack's 186 investigations showed that one litre of cow's milk 
contained from 0.55 to 0.6 gramme, and one litre of woman's 
milk from 1.1 to 1.3 grammes of nucleon. Nucleon can unite 
with lime and fix it in chemical combination. The total phos- 
phorus content of cow's milk is 1.5 grammes, over three times 
that of mother's milk, 0.47 gramme (Siegfried 188 ). 

Stoklasa 187 found that one litre of cow's milk contained 
from 0.9 to 1.13 grammes of lecithin, whereas in one litre of 
human milk there were present from 1.7 to 1.86 grammes of 
lecithin. The same investigator found that one litre of 
woman's milk contained 0.44 gramme of phosphoric acid, and 
one litre of cow's milk contained 1.81 grammes of the same. 



MOTHER'S MILK. 39 

Of the phosphoric acid in milk, then, 0.153 is represented by 
lecithin in woman's milk and 0.091 in cow's milk; of the total 
phosphorus content in woman's milk, thirty-five per cent, exists 
as lecithin, whereas in cow's milk lecithin represents bnt five 
per cent. Lecithin contains from 3.84 to 4.12 per cent, of 
phosphorus ; it is broken up by the process of sterilization into 
cholin, glycerin-phosphoric acid, and fatty acids. 

Variations in Composition. 

Koeppe 16s emphasizes the fact that constant alterations in 
the composition of mother's milk occur from hour to hour 
and day to day. He suggests that the poor results often ob- 
tained from the use of carefully selected pure and sterilized 
milk are due to its uniform consistence, whereas nature's 
product shows constant variations. 

Adriance's analyses show that the milk of primiparse during 
the third month of lactation is richer in fats, proteids, salts, 
and total solids than average milk; the sugar percentage is 
less in the milk of primiparEe. In the milk of multipara? 
at this time there is more sugar and less proteids and fat. 

Leeds 166 considers that lean women in good physical con- 
dition furnish a milk richer in albuminoids than those of 
over-robust habit. 

The composition of milk before and after suckling varies, 
especially in its fat percentage. This is well shown by Carter 
and Eichmond 39 in a table deduced from the observation of 
thirty-seven cases: 

Before suckling. After suckling. 

Per cent. Per cent. 

Water 88.33 88.04 

Fat 2.89 3.18 

Sugar 6.51 6.53 

Proteids 1.99 1.99 

Ash 0.28 0.26 



"ore suckling. 
Per cent. 


After suckling. 
Per cent. 


2.77 


3.94 


5.70 


5.09 


0.98 


0.95 



40 THE ARTIFICIAL FEEDING OF INFANTS. 

Johannessen gives the following differences : 



Water . . 

Fat 

Sugar . . 
Proteids 
Ash ... . 



Johannessen's maximum variation in the fat percentage was 
from 1.51 before to 4.01 after suckling. Forster found more 
marked differences: 



Water. . 

Fat 

Sugar . . 
Proteids 
Ash.... 



Summary. 
If we draw up a table representing the results of the most 
reliable series of analyses of mother's milk, we find that the 
variations are not very great, and that the figures all approxi- 
mate to a general average. The high estimates for the proteids 
obtained by Pfeiffer, Leeds, and Eichmond may be partly 
accounted for by the fact that the Ritthausen method, which 
they employed, gives uniformly high results; besides this, 
the majority of Leeds's and Richmond's analyses were of 
samples taken during the first three or four weeks of lacta- 
tion (including the colostrum period), when all observers are 
agreed that the percentage of proteids is uniformly high. 
Pfeiffer, Leeds, and Richmond found that the proteid per- 



Fore-milk. 


Middle milk. 


Strippings. 


Per cent. 


Per cent. 


Per cent. 


90.24 


89.68 


87.50 


1.70 


2.77 


4.51 


5.56 


5.70 


5.10 


1.13 


0.94 


0.71 


0.46 


0.32 


0.28 



MOTHER'S MILK. 



41 



centage diminished after the first month of lactation. On 
the other hand, the low estimates of the total proteids reached 
by Meigs and Johannessen are probably explained by the fact 
that most of their samples came from needy women in poor 
lrygienic surroundings. The tables of Pfeiffer, Schlossmann, 
and Adriance are in accord in showing that the total proteids 
are high at first bnt soon fall, to maintain a fairly constant 
average during the height of lactation. According to Schloss- 
mann, Adriance, and Soldner, the total proteids show a ten- 
dency to gradually diminish until (towards the end of the first 
year) they rarely exceed one per cent. 



§ 



Number of cases. 


160 


80 


25 


90 


40 


43 


218 


120 




Per 
cent. 


Per 
cent. 


Per 
cent. 


Per 

cent. 


Per 
cent. 


Per 
cent. 


Per 
cent. 


Per 
cent. 


Fat 


3.11 


4.13 


3.21 


3.07 


3.8 


4.28 


4.83 


3.83 


Sugar 


6.3 


6.93 


4.67 


6.59 


6.0 


7.4 


6.95 


6.56 


Proteids 


1.94 


1.99 


1.10 


1.97 


1.7 


1.05 


1.56 


1.30 


Salts 


0.19 


0.20 




0.26 


0.20 


0.10 




0.20 


Water 


88.22 


86.73 




88.04 


88.5 


87.16 




87.80 


Solids 


11.76 


13.26 




11.89 


11.70 


12.83 




12.20 



On the basis of the first five tables quoted above, which he 
says represent the results of the most reliable analyses of 
human milk, Eichmond estimates the following to be the prob- 
able mean composition of normal human milk after lactation 
has become regular: 

Per cent. 

Water 88.2 

Fat 3.3 

Sugar 6.8 

Proteids 1.5 

Ash 0.2 



42 THE ARTIFICIAL FEEDING OF INFANTS. 

The tables of Schlossmann and Adriance deserve special 
notice, since they represent the result of analyses covering the 
whole period of lactation and carried out by uniform methods. 

Kichmond's average must not be considered to represent any- 
thing more than a general mean. At all times of lactation 
analysis of the breast-milk will show greater or less variations, 
in the proteid and fat content especially. All that can safely 
be said is that one and a half per cent, of proteids constitutes 
a proportion which is very constantly found during the height 
of lactation. Variations above and below this figure are fre- 
quent, so that we may regard two per cent, as a high and 
one per cent, as a low proteid content in mother's milk. Over 
two and under one per cent, may be considered abnormal ex- 
cept at the beginning and end of lactation. 

The presence of 0.5 per cent, of soluble proteids in mother's 
milk, in the form of lactalbumin and lacto-globulin, is now 
generally accepted. These substances represent from one-third 
to one-fourth of the total proteid content, they are readily 
digestible, and apparently are present in larger proportion 
during the first months of life, when the child's powers of 
assimilation are little developed. 

The percentage of fat in mother's milk varies normally be- 
tween three and four and a half. Below two and over five 
are abnormal. Fat is the most variable constituent in mother's 
milk ; the proportion is not affected by the period of lactation. 
The fat of mother's milk differs from that of cow's milk in 
containing fewer volatile acids; it is also in a much finer 
state of emulsion, and is therefore easier of digestion. 

The percentage of sugar is a very constant one, varying 
from six to seven. It is lowest during the colostrum period; 
from that time on it steadily increases throughout lactation. 
The average percentage of sugar at the height of lactation may 
be estimated as six and one-half. It is readily assimilated. 

The percentage of salts averages 0.2. It is highest at first 
and diminishes steadily during lactation. In contrast to cow's 



MOTHER'S MILK. 43 

milk, nearly all of the phosphorus exists in organic combina- 
tion.* 

The ratio of the nitrogenous to the non-nitrogenous elements 
in woman's milk is about 1 to 7.6; in cow's milk it is 1 
to 2.3. 

* Schlossmann has recently asserted that the previous methods of 
analysis to determine the phosphorus content of milk are open to grave 
objections, so that he is no longer prepared to state that an essential 
difference exists between mother's milk and cow's milk as regards 
the amount of organic phosphorus present. (See Edlef sen's article, 
Chapter III.) 



CHAPTER III. 

COW'S MILK. 

Practically, the secretion of the domesticated milch-cow 
has come into universal use for the artificial feeding of in- 
fants. As substitutes for cow's milk, mare's milk, goat's milk, 
and ass's milk have been recommended, especially the latter. 
H. von Ranke 124 states that ass's milk contains, according 
to the latest authorities, casein and albumin in the ratio of 
one hundred to eighty-one (Soxhlet and Scheibe) ; [casein 1.32 
and albumin 0.34 (Richmond)] ; fat about one per cent., sugar 
six per cent., and ash from 0.4 to 0.5 per cent. Notwithstand- 
ing its low fat content, it is well adapted for use in the first 
eight to twelve weeks of life, and experience has proved its 
value. The results obtained have been encouraging, especially 
in Paris, where it is largely used by the better classes (its 
price is one dollar a quart). The cost and difficulty of ob- 
taining ass's milk have prevented its coming into general use; 
the same may be said of goat's and mare's milk. 

Reaction. 
Cow's milk has usually, when fresh, an amphoteric reaction. 
At times it may be feebly alkaline. With phenol-phthalein 
the reaction is always acid (Klimmer). 

At ordinary temperatures milk soon becomes acid on stand- 
ing. 

Specific Gravity. 

Allowing for differences of temperature of the milk when 
tested, Richmond finds that the specific gravity of the mixed 
milk of the herd rarely falls outside of the limits of from 
44 



COW'S MILK. 45 

1030 to 1034, with an average of 1032. This average corre- 
sponds very closely with those obtained by other investigators, 
with the exception of Leeds, whose figures are decidedly higher 
(1039.7), and Klimmer, who finds variations at a temperature 
of 15° C. of from 1027 to 1040. 

Eichmond. 121 The specific gravity is dependent on two 
factors : the amount of solids not fat, which, being dissolved 
in water, raise the specific gravity; and the fat, which, being 
lighter than water, lowers it. 

"By removing the fat as cream (with a small proportion 
of the other constituents), the specific gravity of the milk is 
raised. By the addition of water, the specific gravity is low- 
ered. The specific gravity has been, and' is, largely used as a 
test to show the addition of water to milk; for the detection 
of large amounts of water in milk it has some value. 

" As a preliminary test, estimating the specific gravity is 
of the greatest importance and should never be neglected; as 
an absolute test, it is liable to be greatly misleading. This 
is shown by the following facts. 

" I. With milk of 1034 specific gravity at least ten per 
cent, of water could be added before it would be suspected by 
this test. 

" II. If the cream were all removed from a milk of 1032 
specific gravity we would have a product of about 1036 specific 
gravity, and an addition of rather more than ten per cent, 
of water would bring the specific gravity back to 1032. 

" III. If to milk of 1032 specific gravity sufficient cream 
be added to raise the percentage of fat four per cent., the 
specific gravity will be found to be about 1028." 

Mixed Milk. 
Practically, all authorities are agreed in recommending the 
use of the mixed milk from a herd, in order to dilute the harm- 
ful products which may be present in the milk of a single 
cow. 



46 THE ARTIFICIAL FEEDING OF INFANTS. 

Description. 
By far the most satisfactory account of the composition and 
characteristics of cow's milk is to be found in H. Droop 
Eichmond's " Dairy Chemistry." 121 According to this author, 
milk is essentially an aqueous solution of lactose, albumin, 
and certain salts, holding in suspension globules of fat, and 
containing casein in a state of semi-solution, together with 
mineral matters. The composition of cow's milk is given as 
follows, on the basis of two hundred thousand analyses (Eng- 
lish) : 

Per cent. 

Water 87.10 

Fal 3.90 

Lactose 4. 75 

Casein 3.00 

Albumin 0.40 

Ash 0.75 

Paul Yieth (for twelve years analyst to the Aylesbury Dairy 
Company) gives the average ratio between lactose, proteids, 
and ash in milk as 13 to 9 to 2. Eichmond found this marvel- 
lously exact. 

Variations in composition may occur in abnormal milk : 

Per cent. 

Fat from 2.79-10.5 

Lactose from 1.91- 4.66 

Proteids from 3.35- 4.58 

Ash from 0. 76- 0.94 

In England, where cows are milked twice a day, the evening 
milk is almost invariably richer in fat than the morning milk. 
When the interval between milkings is twelve hours, this is 
far less noticeable than when it is from nine to ten hours 
during the day and fourteen to fifteen hours during the night. 

Colostrum contains less sugar, a fat very poor in volatile 



COW'S MILK. 47 

acids, and a high amount of nitrogenous compounds which 
differ from those of normal milk. 

At least four days should elapse after parturition before 
the milk is used, although the milk does not regain its normal 
composition before the lapse of from eight to fourteen days. 
As lactation advances the fat, casein, and mineral salts in- 
crease and the sugar decreases (the reverse of what occurs 
in human milk) . 

The English Society of Public Analysts requires the follow- 
ing standard in cow's milk: three per cent, by weight of fat 
and eight and a half per cent, by weight of solids not fat. 
These limits have been accepted as satisfactory by the great 
majority of analytical chemists in the country. Vieth has 
found that a bad season for haymaking is nearly always fol- 
lowed by a deterioration in the quality of the milk in the 
following winter and spring. Long periods of cold and wet 
or heat and drought — when the cattle are at pasture — unfavor- 
ably influence the quantity and quality of the milk. A limit 
of three per cent, fat is reasonable for the mixed milk of a 
whole herd; far more commonly the milk falls below the 
standard of eight and a half per cent, of solids not fat. For 
all practical purposes the triple standard of eight and a half 
per cent, solids not fat, 0.5 per cent, total nitrogen, and 0.70 
per cent, ash may be adopted for the purpose of judging 
whether or not the milk is of genuine composition. 

Composition of Milk. 

Langlois 38 (French). Soxhlet 99 (German). Leeds 93 (American). 
Per cent. Per cent. Per cent, 

Fat 4.0 3.69 3.75 

Sugar 5.0 4.88 4.42 

Proteids 3.4 3.55 3.76 

Ash 0.6 0.71 0.68 

Total solids 13.0 ... 

Water 87.0 87.17 



Ayrshire. 


Hoi stein. 


Jersey. 


Per eeiit. 


Per cent. 


Per cent. 


3.89 


2.88 


5.21 


4.41 


4.33 


4.52 


4.01 


3.99 


3.99 


0.73 


0.74 


0.71 


86.96 


88.06 


85.57 



American 

grade. 
Per cent. 


Common 

native. 

Per cent. 


4.01 


3.69 


4.36 


4.35 


4.06 


4.09 


0.74 


0.73 


86.83 


84.14 



48 THE ARTIFICIAL FEEDING OF INFANTS. 

The composition of milk varies considerably, according to 
the breed of cattle. Mr. Gordon, of the Walker-Gordon Labo- 
ratory, has collected the results of over one hundred and forty 
thousand analyses, sixty thousand of which represent the milk 
of the American grade of imported cow and the common na- 
tive. 



Durham. 
Per cent. 

Fat 4.04 

Sugar 4.34 

Proteids 4.17 

Ash 0.73 

Water . 86.72 



" Leaving out the Jerseys' milk, the following represents 
very closely the average composition of cow's milk as the 
(American) physician has to do with it in infant feeding" 
(Holt). 

Average composition of cow's milk (American) : 

Per cent. 

Fat 3.50 

Sugar 4.30 

Proteids 4.00 

Ash 0. 70 

Water 87.00 

Provided the cattle are healthy, Holt does not consider that 
any special breed should be selected for the purposes of infant 
feeding. As fat is the most variable constituent of milk, the 
determination of its percentage suffices for all practical pur- 
poses. 

In a recent interview Henry Lerfmann states that the com- 
position of good milk is as follows: 



COW'S MILK. 49 

Per cent. 

Fat from 3.5-4.5 

Sugar from 4. 7-4. 9 

Proteids from 3.5-3.8 

Ash from 0. 7-0.8 

The composition of cow's milk as given by Droop Bichmond 
can undoubtedly be accepted as an average of English dairies, 
in view of the large number of analyses it represents. Holt's 
figures vary from Bichmond's, but have a more distinct value 
to the American physician because they represent what might 
be called an American average (one hundred and forty thou- 
sand cases). The principal differences between his figures 
and those of Eichmond consist in the higher proteid per- 
centages. The tables of Langlois, Soxhlet, and Leeds have been 
selected because they represent the work of reliable investi- 
gators: many other analyses might have been cited, but as 
no two of them are identical, their enumeration would serve 
no useful purpose. The fact cannot be emphasized too strongly 
that the milk of even large herds of cattle, much more the 
milk of a single cow, is apt to vary markedly from any average 
that can be established, owing to differences in the breed of 
cattle, the methods of feeding, the season of the year, etc. 
Secondly, no rational average can be deduced from any but a 
large number of examinations made under unvarying condi- 
tions and with unvarying methods. Finally, no average can 
be expected to do more than establish a mean which a good 
milk may reasonably be expected to approximate. 

The figures of Holt may be accepted as such an average, 
but whether the milk of a given herd will resemble it can be 
determined only by analysis. The milk of a carefully fed herd 
varies very little from day to day, so that an occasional test 
is all that is necessary to be assured of the proportion of the 
different ingredients. It is a great advantage of certified milk 
that its composition has to satisfy a definite standard, so that 
we may know what percentages of the different elements we 

4 



Solids. 


Fat. 


Ash. 


>er cent. 


Ter cent. 


Per cent 


13.34 


3.88 


0.85 


15.40 


6.74 


0.81 


17.13 


8.12 


0.82 



'50 THE ARTIFICIAL FEEDING OF INFANTS. 

are administering, especially the amount of fat present, which 
is the most variable ingredient in cow* s milk. 

The use of the strippings of cow's milk in infant feeding 
has been advocated by some authors. To illustrate the varia- 
tions in its composition, the following table is appended: 

Harringtons analyses : S7 



Water. 
Per cent. 

Fore-milk 86.66 

Middle milk 84.60 

Strippings 82.87 



Richmond states that it is not unusual to find more than 
ten per cent, of fat in strippings. 

Peoteids — Albuminoids. 

Since the digestion of the albuminoids of cow's milk consti- 
tutes one of the greatest difficulties in the artificial feeding of 
infants, it seems advisable to discuss their physical and chemi- 
cal properties at some length. The consideration of the other 
ingredients follows, while the various methods of preparing 
milk for the infant will be detailed in a later chapter. 

KicioioxD. 121 " The curd of cow's milk produced by the ad- 
dition of acid is found to consist of casein which is combined 
with phosphates of the alkaline earths. In human milk this 
is replaced by a similar albuminoid which is not combined with 
phosphates. 

" Besides casein there is a second albuminoid called albumin. 
This differs from casein in not being precipitated by acids and 
in being coagulable by heat. Other albuminoids have been 
described in milk, but many of them are only decomposition 
products of casein or albumin, which were formed during the 
process adopted for the removal of the other albuminoids. 



COW'S MILK. 51 

" Evidence has been adduced of a third albuminoid, lacto- 
globulin. This is coagulable by heat and precipitated by neu- 
tral sulphates, tannin, etc. Kennin does not coagulate it; 
it only occurs in traces,, and it is not known whether it differs 
chemically from serum-globulin. The chief characteristic of 
lacto-globulin is its solubility in sodium chloride solutions, 
even when acidified. 

" Traces of Storches 7 mucoid-proteid also exist in milk, and 
it is possible that traces of albumose are formed during the 
decomposition to which milk is prone; true peptone has been 
proved to be absent. The casein in milk is probably in the 
state recently described by Picton and Linder as pseudo-solu- 
tion. This state is due to the existence of particles in solution 
which are not sufficiently large to settle under the influence 
of gravity, but which will interfere with the passage of light. 
They can be separated by electricity or by filtering through a 
porous jar. They also show that there is no sharp dividing 
line between crystalloids and colloids in solution, substances 
in pseudo-solution, and substances in suspension. In milk we 
have these four states represented: the fat is in suspension, 
the casein in pseudo-solution, the albumin in solution as a 
colloid, and the lactose in solution as a crystalloid. These 
four states are probably due to the size of the conglomerates 
of molecules or particles." 

Properties of the Albuminoids. 

" Our present knowledge of the albuminoids is far from 
complete, though much work has been done on the subject. 
This is due to the fact that it is extremely difficult to obtain 
these compounds in anything like a state of purity. The 
difficulty is still further increased by the peculiar behavior 
of casein in retaining calcium salts if once it has been brought 
into contact with them, as is the case in milk. 

" The milk albuminoids are bodies of complex composition 



52 THE ARTIFICIAL FEEDING OF INFANTS. 

containing carbon, oxygen, nitrogen, hydrogen, phosphorus, 
and sulphur. The way in which these elements are combined 
is not known. . . . The molecule of albuminoids is very com- 
plex, as is evident by their being indiffusible bodies. By the 
action of acids and certain enzymes — e.g., peptase (pepsin) — 
they are resolved into simpler bodies which become more and 
more diffusible as the decomposition advances." 

Of the various albuminoids existing in cow^s milk we will 
describe those four of whose presence we have the strongest 
evidence : casein, lactalbumin, lacto-globulin, and Storehes' 
mucoid-proteid. 

" Casein is precipitated by saturating a solution with sodium 
chloride, magnesium sulphate, and ammonium sulphate. Glob- 
ulin is soluble in a saturated solution of sodium chloride, but 
precipitated by magnesium sulphate and ammonium sulphate. 
Albumin is soluble in a saturated solution of sodium chloride 
and magnesium sulphate, but precipitated by saturation with 
ammonium sulphate, while Storehes' mucoid-proteid is not in 
solution. 

'* Casein and globulin are precipitated by acids, while albu- 
min (and globulin if much salt is present) is not so precipi- 
tated. Casein has the remarkable property of being acted upon 
by chymase, the enzyme of rennet, with the formation of an 
insoluble product. Albumin is coagulated by the action of 
heat, T0° C. being sufficient to precipitate a great portion. 
Casein (and globulin?) are removed from solution by filtration 
through a porous cell, while albumin remains dissolved. All 
three are soluble in alkalies and precipitated by tannin and 
phospho-tungstic acid and are insoluble in alcohol." 

Casein. — " Casein has the property of forming an opalescent 
solution when dissolved in the least possible excess of sodium 
phosphate and a small quantity of calcium chloride is added: 
it gives then a solution having the appearance of milk. It is 
probable that milk contains casein in this form. Casein has 
a peculiar affinity for calcium salts, especially the phosphate. 



COW'S MILK. 53 

" Analyses do not yield very concordant results, bnt the most 
probable composition of casein is as follows: 



Carbon. Hydrogen. Nitrogen. Sulphur. Phosphorus. Oxygen. 

Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. 

53.13 7.06 15.78 0.77 0.86 22.40' 



Hammarsten's and W T roblewsky's analyses show the following 
differences between mother's milk casein and cow's milk casein : 



Hydro- Nitro- Phos- Sul- Oxy- 

Carbon. gen. gen. phorus. phur. gen. 

Per Per Per Per Per Per 

cent. cent. cent. cent. cent. cent. 

Breast-milk casein (Wroblewsky) 52.24 7.72 14.97 0.68 1.17 23.66 

Cow's milk casein (Hammarsten) 53.00 7.00 25.70 0.85 0.80 22.65 



Lactalbumin. — " This albuminoid has the property charac- 
teristic of albumins of being coagulated by raising the tem- 
perature of its solution to 70° C. The precipitation is never 
complete, since, according to Sebelien, as much as twelve per 
cent, may be left in solution/' 

He gives the following table of its composition : 



Carbon. Hydrogen. Nitrogen. Sulphur. Oxygen. 

Per cent. Per cent. Per cent. Per cent. Per cent. 

52.19 7.18 15.77 1.73 23.13 



It differs from casein in containing no phosphorus and about 
twice as much sulphur. The amount of lactalbumin in cow's 
milk is variously estimated at from 0.3 to 0.5 per cent, by 
Lehmann, Klimmer, and other investigators. 

Whey-Proteids. — When a solution of rennin is brought 



54 THE ARTIFICIAL FEEDING OF INFANTS. 

into contact with cow's milk at a moderate temperature (from 
90° to 100° F.) the casein is coagulated and the serous portion 
of the milk separates as a white translucent fluid called whey. 
This contains the whey-proteids, part of the salts, the sugar 
of milk, together with a small amount of fat. The whey-pro- 
teids comprise the lactalbumin and lacto-globulin of milk, 
besides a soluble proteid similar to albumin, which is split off 
from the casein by the action of the rennin (Leffmann). 

Both Eotch and Cautley, by a series of experiments on the 
coagulability of milk with acetic acid, have endeavored to show 
that, in order to simulate the curd produced in mother's 
milk by the addition of acid, cow's milk must be diluted with 
from four to five times its bulk of water; or, in other words, 
that there is from four to five times as much caseinogen in 
cow's milk as in mother's milk. These results cannot be ac- 
cepted as conclusive, for we know that coagulation by rennet 
is the first step in the digestion of casein in the infant's stom- 
ach; hence the natural conditions cannot be said to have been 
imitated in the test-tube experiments. 

Fat. 

Eichmond. 121 " The fat in cow's milk is of complex com- 
position. It differs from all other fats in that it contains 
compound glycerides, partly built up of fatty acids of low 
molecular weight. The general consensus of opinion at the 
present day among chemists is, that the fat-globules in milk 
are not surrounded by a membranous envelope, therefore there 
is a true emulsion. There is very little doubt that a layer of 
some sort exists, probably formed by a force similar to capillary 
attraction. Leeds says that this layer consists of a number of 
albuminous molecules which have been condensed by molecular 
attraction and thereby hinder the coalescence of the fat par- 
ticles. 

" From the mean results obtained by different observers, the 
average composition of the fat of milk appears to be as follows : 



COW'S MILK. 55 



Per cent. Per cent. Per cent. 

Butyrin 3.85, yielding 3.43 fatty acids and 1.17 glycerol. 

Caproin 3.60, yielding 3.25 fatty acids and 0.86 glycerol. 

Caprylin 0.55, yielding 0.51 fatty acids and 0.10 glycerol. 

Caprin 1.90, yielding 1.77 fatt}^ acids and 0.31 glycerol. 

Laurin 7.40, yielding 6.94 fatty acids and 1.07 glycerol. 

Myristin 20.20, yielding 19.14 fatty acids and 2.53 glycerol. 

Palmitin 25.70, yielding 24.48 fatty acids and 2.91 glycerol. 

Stearin 1.80, yielding 1.72 fatty acids and 0.19 glycerol. 

Olein, etc 35.00, yielding .33.60 fatty acids and 3.39 glycerol. 



Total 100.00 Insoluble. 87.65 Total. . 12.53 

Total.. 94.84 

" Besides the constituents enumerated above, there also exist 
traces of cholesterol (which doubtless replace a portion of the 
glycerol), lecithin, a coloring matter, and possibly also a hydro- 
carbon. 

" Lecithin exists in small quantities in butter fat ; on saponi- 
fication it gives glyceryl-phosphoric acid, fatty acids, and chol- 
ine; it contains 3.84 per cent, of phosphorus and gives 8.8 
per cent, of phosphoric acid on oxidation. The quantity does 
not exceed 0.5 per cent, of the fat. There is also a coloring- 
matter of unknown composition and an odoriferous principle." 

Sugar. 

" The sugar in cow's milk is said to be not identical with that 
in human milk. 121 

" Lactose is not fermentable by ordinary yeast and is not 
acted upon by invertase, diastase, rennet, pepsin, and trypsin. 
There exists, however, an enzyme called lactase, which is found 
in fresh kephir grains, which hydrolyzes lactose to glucose and 
galactose. The bacteria which decompose lactose with the pro- 
duction of lactic acid are acted upon inimically by acids, so that 
not much more than one per cent, of lactic acid is formed un- 
less the solution is kept neutralized." 



56 THE ARTIFICIAL FEEDING OF INFANTS. 

Salts. 

" The presence of citric and acetic acids in milk has not 
been universally accepted. Bechamp maintains that casein and 
albumin exist in milk as salts of alkalies. There is much to 
recommend this view. 121 

" Casein has a peculiar affinity for calcium salts, especially 
the phosphates, from which it is extremely difficult to free it; 
nor has it been found possible to dissolve casein to an appre- 
ciable extent without an alkali being present. 

" Milk does not become sour until appreciable acidity has 
developed. The phenomenon of coagulation of milk after this 
has occurred, and on the application of heat, is probably due 
io the acid developed displacing the casein from its combina- 
tion with an alkali, and, when this is wholly accomplished, 
to the free acid manifesting its properties. Soldner has also 
adduced evidence in proof of this view." 

Harrington and Kinnicutt. Richmond. 

Ash of mother'.* milk. Ash of cow's milk. 

Per cent. Per cent. 

Lime 15.69 20.27 

Magnesia 1.92 2.80 

Potash 24.77 28.71 

Soda 9.19 6.67 

Phosphoric acid 10.73 29.33 

Chlorine 20.11 14.00 

Carbonic acid 7.97 0.97 

Sulphuric acid 2.19 a trace 

Ferric oxide, etc 0.40 0.40 

Silica 0.70 

Oxygen (calculated ) 6. 16 .... 

99.83 103.15 

Less oxygen and chlorine 3. 15 

Since by oxidation the phosphorus and sulphur of the pro- 
teids are altered into phosphoric and sulphuric acids, and the 



COW'S MILK. 



57 



carbon is changed into carbonic acid, the ash does not truly 
represent the mineral constituents of milk. About eight per 
cent, of the phosphoric acid present in the ash is derived from 
the phosphorus of the casein. 

Comparison between the Salts of Mother s Milk and Cow's 

Milk. 



Mother's Milk. 
Harrington and Kinnicutt. 

Per cent. 

Sodium chloride 21.77 

Potassium chloride 12.05 

Potassium sulphate 8.33 

Potassium carbonate 23.47 

Calcium phosphate 23.87 

Calcium carbonate 2.85 

Calcium sulphate 2.25 

Calcium silicate 1.27 

Magnesium carbonate 3. 77 

Iron oxide and alumina .... 0.37 



Cow's Milk. 
Adapted from Sbldner. 

Per cent. 

Sodium chloride 10.62 

Potassium chloride 9.16 

Potassium citrate 5.47 

Potassium phosphate 21.99 

Calcium phosphate 16.32 

Calcium citrate 23.55 

Lime combined with proteids 5.13 

Magnesium citrate 4.05 

Magnesium phosphate 3.71 



Leifmann considers that Soldner's table is in part theoreti- 
cal. 

Edlefsen". 244 While cow's milk is richer than mother's milk 
in phosphorus, only the smaller part of it is in organic com- 
bination in the former case. The remainder is present as 
inorganic phosphates. In woman's milk, on the other hand, 
all the phosphorus is in organic combination: according to 
Schlossmann, thirty-five per cent, in the casein, thirty-five per 
cent, in the nucleon, and thirty per cent, in the lecithin, as 
against thirty-five per cent, in the casein, eleven per cent, in 
the nucleon and lecithin, and fifty-four per cent, in inorganic 
combination in cow's milk. Since the casein contains phos- 
phorus, it may be considered a nucleo-albumin ; but whereas 
the nuclein contained in it is not absorbable as such, nucleon 



58 THE ARTIFICIAL FEEDING OF INFANTS. 

and also lecithin are very easy of absorption. The organic 
phosphorus combinations are much more important for the 
nourishment and growth of the infant than the inorganic. 
According to the analyses of the faeces and urine by Eohmann 
and Steinitz, the administration of inorganic phosphates leads 
to an only slight gain in phosphorus. In the proportions in 
which cow's milk is given to the infant, there is only a small 
amount of casein and still less nucleon and lecithin. As far 
as the nuclein present in this small amount of casein is con- 
cerned, it can be completely absorbed. Nuclein, according 
to Popoff, and paranuclein, according to Gumlich, Sandmeyer, 
Micko, and others, are made soluble by the pancreatic fer- 
ments; for the most part, they are converted into nuclein- 
phosphoric acid. In this respect there do not seem to be any 
essential differences between cow's milk and mother's milk 
casein. 

With regard to phosphorus metabolism, Paul Miiller has 
shown that the absorption of the phosphorus of cow's milk, 
when not introduced in too large amount, is just as complete 
as that of the phosphorus in mother's milk ( ? Editors ) . 
Eubner and Heubner have demonstrated that the casein of 
cow's milk, if it is not given in excess, is as well absorbed as 
that of mother's milk (? Editors). But when diluted cow's 
milk is given, the amount of organic phosphorus present as 
well as that of the organic sulphur in the lactalbumin is very 
small. Up to the present we have found no means of com- 
pensating for the greater richness of mother's milk in nucleon 
and lecithin, which increases as the secretion of milk becomes 
more abundant. We know also that boiling destroys the leci- 
thin (Baginsky), and if the application of heat is prolonged, 
also the nucleon; the nuclein of the casein is probably also 
modified. These facts perhaps explain why infants fed for a 
long time on milk and milk preparations which have been sub- 
jected for a considerable period of time to excessive heat (such 
as Scherff's, Hesse's, or Yoltmer's Milk, Soxhlet's Mixture, etc.) 



COW'S MILK. 59 

sometimes develop scurvy. The beneficial results from the 
administration of phosphorus and cod-liver oil in rickets make 
it probable that this disease is due, in great measure at least, 
to an insufficient amount of organic phosphorus in the food. 

The diminution of the percentage of salts in mother's milk 
as lactation advances is compensated by the increased quantity 
of the milk secreted; so that the total amount furnished the 
infant suffices for its growth and especially for the bony de- 
velopment. 

Gases. 

Richmond. 121 The gases in milk have no practical im- 
portance. Oxygen, nitrogen, and carbon dioxide are present 
when it is fresh, probably due to absorption from the air during 
and after milking. On standing, the oxygen decreases and 
carbon dioxide increases, probably owing to aerobic bacteria. 

Thorner 128 found that, directly after being drawn, cow's 
milk contained from fifty-seven to eighty-six cubic centimetres 
per litre of carbon dioxide, oxygen, and nitrogen. The serum 
of acid milk contains even larger amounts, — from one hundred 
and fourteen to one hundred and seventy-two cubic centimetres 
per litre. A large portion of this gas disappears in centrifuga- 
tion; on the average, from twenty-seven to fifty-four cubic 
centimetres remain. Boiling and sterilization still further 
reduce the gas content to from fifteen to nineteen cubic centi- 
metres per litre. By keeping in closed bottles an increase 
occurs, because, in bottles not heated directly after filling, car- 
bon dioxide fermentation occurs. The unpleasant taste of 
milk sterilized in open bottles depends on the disappearance 
of carbon dioxide and not on chemical changes. If carbon 
dioxide can be incorporated artificially with such milk, the 
pleasant taste will return. 

Separated Milk. 
Richmond. 121 Skimmed milk contains from 0.4 to over 
two per cent, fat; in separated milk the limit of 0.3 per 



60 THE ARTIFICIAL FEEDING OF INFANTS. 

cent, fat is rarely exceeded. By the removal of the fat the 
percentage of the other constituents is slightly increased. 

By the action of the separator a slimy residue is left con- 
taining: (1) Inorganic impurities, such as dirt. (2) Vege- 
table matter derived from fodder, such as hay or leaves. (3) 
Substances derived from the cow, such as hair, pavement 
epithelium from the udder, empty gland cells (which form 
a very large portion of the slime), numerous micro-organisms, 
pus, blood, etc. 

The quantity of slime equals 0.04 part in one hundred parts 
of milk separated ; in dirty milk it may amount to 0.15 per cent. 

The number of micro-organisms in cream and separated milk 
is not appreciably diminished by this process, and a mixture 
of them keeps no better than the milk from which they were 
separated. Straining through a fine wire sieve or through fine 
muslin or swan's down is usually practised. This removes the 
grosser impurities, but the amount of dirt removed in this way 
does not exceed 0.0025 per cent. Filtration through layers of 
gravel or sand is practised in some Danish, German, and Eng- 
lish dairies; it has no advantage over the previous method. 

Variations in the Composition or Cow's Milk. 
Edsall. 50 In the course of metabolism experiments carried 
out at the Pepper Clinical Laboratory the author estimated 
the proteids of milk from one dairy for a period of ten months, 
using the Kjeldahl method. He found daily variations in the 
proteid content from 2.7 to 4.1 per cent. These occurred even 
in winter, when the cows were given regular fodder; in the 
spring, especially when the animals were fed largely on fresh 
grass, the daily variations were so great that calculations based 
upon any fixed percentage were liable to be very uncertain. 
It will almost always be found that the proportion of proteids 
is below the commonly accepted four per cent. In the same 
series of estimations the fat percentage varied from 3.2 to 
nearly six. 



CHAPTER IV. 
DIGESTION. 

The digestive tract of the new-born and of the infant pre- 
sents many features, both anatomical and physiological, in 
which it varies materially from that of the adult. The se- 
cretion of the different digestive ferments is slow in being 
established; in fact, it is only towards the end of the second 
or the beginning of the third year that the digestive functions 
approach in capacity those of the fully developed organism. 
It seems advisable, then, for the proper comprehension of the 
subject of infant feeding, to consider at some detail the anat- 
omy of the digestive tract and the physiology of the organs 
of digestion. 

Monti." The salivary and parotid glands are small and 
poorly developed at birth, and the secretion of the salivary 
ferments, according to most observers, is slow in becoming 
established, not attaining decided power before the period of 
dentition. Soltau Fenwick 52 concludes, on the basis of nu- 
merous experiments, that the salivary secretions first have a 
decided and constant influence on starch about the fourth 
month, and Korowin found that at this time one and a half 
cubic centimetres of saliva appeared from five to seven min- 
utes after taking food. On the other hand, Kriiger asserts 
that he has found traces of ferment in the secretions of the 
salivary glands of a seven months foetus (Monti and Bagin- 
sky). The parotid secretion contains more diastatic ferment 
than the other salivary glands (Zweifel and Korowin"). 
While ptyalin is found in the parotid at birth and in the 
submaxillary glands about the fourth week, the amylolytic 
action of these glands becomes fully established only towards 

61 



62 THE ARTIFICIAL FEEDING OF INFANTS. 

the end of the first }^ear (Monti/ 9 Thomson 143 ). Jacobi, 76 
on the other hand, states that the saliva possesses diastatic 
action after the first month, although its secretion is apt to 
be scanty in the very young and in cases of debility. 

The truth of the matter would seem to be that the activity 
of the parotid and salivary glands varies in different infants. 
As a rule, however, the salivary secretions are not present in 
sufficient quantity to possess any considerable diastatic action 
on starchy substances before the fourth to the eighth month,— 
that is, about the period of dentition. 

Anatomy of the Stomach. 
Monti." The infant's stomach at first lies in an almost 
vertical position, and the fundus is poorly developed; Monti 
also lays stress on the slight degree of development of the 
greater curvature. Marfan and Thomson make similar state- 
ments. Thomson considers that the shape of the stomach is 
originally tubular. The capacity of the greater curvature 
stands in ratio to the capacity of the entire organ as one 
to five in the infant, whereas in adults it is as one to two 
(Moritz). According to Fleischmann, the layer of oblique 
muscular fibres is not present in the infant's stomach, nor 
are the long fibres described by Henle which radiate from the 
pyloric valve. The fibres at the fundus are the most poorly 
developed. Peristaltic movements increase in strength towards 
the pyloric end of the stomach and thus tend to approximate 
the cardia to the pylorus. Although the musculature is poorly 
developed, peristalsis will normally empty the stomach of its 
contents in from one and a half to two hours (Leo and Van 
Puteren) ; according to Biedert, in from two to two and a 
half hours. When digestion is difficult, the time required 
is longer and evacuation may be incomplete. Vomiting occurs 
easily, owing to the poor development of the fundus, the weak 
contraction of the cardiac sphincter, and the fluid consistence 
of the stomach contents (Monti). After ten months the mus- 



DIGESTION. 63 

cular coat of the stomach resembles that of adult life (Mar- 
fan). 

The lab-glands are less numerous than in the adult stomach 
(Baginsky). Their form is funnel-shaped, and they are evenly 
distributed over the whole gastric surface. The multilocular 
glands are scattered, being most numerous at the p}dorus ; on 
the other hand, the mucous glands are more plentiful than in 
adult life; they are most thickly clustered at the pylorus and 
are least numerous at the cardia (Monti). The orifices and 
lumina of the gastric glands are greater than in adult life; 
the differentiation of the chief cells and the parietal cells 
occurs at different times in different subjects (Marfan). 

Gastric Capacity. 
Marfan. 105 The capacity of the infant's stomach is a varia- 
ble factor, depending on the weight, the kind of food that is 
given, and the size of the child's body. Marfan has drawn 
up an average table based on the figures given by Beneke, 
Fleischmann, Frolowsky, D' Astros, and Zuccarelli. The ca- 
pacity at birth is from forty to fifty cubic centimetres; at 
one month, sixty to seventy cubic centimetres ; at three months, 
one hundred cubic centimetres; at five months, one hundred 
and fifty to two hundred cubic centimetres ; from six months 
to one year, two hundred to two hundred and fifty cubic centi- 
metres ; at two years, three hundred and fifty cubic centimetres. 
These figures represent average values and enable us to de- 
termine the existence of dilatation of the stomach in the 
cadaver. They have also been used as a basis for the amount 
to be given at each meal in artificial feeding. We must not 
draw too rigid conclusions from these figures, for the capacity 
of the stomach is without doubt smaller in the living than 
in the cadaver. Besides, it has not been proved that it is 
necessary for a meal completely to distend the stomach. During 
nursing a portion of the milk ingested probably passes im- 
mediately from the stomach into the intestines. 



64 



THE ARTIFICIAL FEEDING OF INFANTS. 





Bexeke, and 
Frolowsky, " 
from actual 
measurements. 


o 

■8 

m 
8 J 


s 

63 
'A 

Si 


a -5 ~ 

°-51 

"** £ ^ 


as 

K o 




Cc. 


Cc. 


Cc. 


Cc. 


Cc. 


First dav 


40-45 


36 


40-50 


29.4 




First week 


46-50 




Second week 


70-72 


45 

60 


80-90 
85-110 


70.5 




Third week 


76-105 




Fourth week 


100-122 


90 


Sixth week 




68 
72 


120-135 


96.6 




Eighth week 


140-158 


100 


Tenth week 




128 
135 


140 


118.8 




Twelfth week 


150-167 


110 


Four months 


160-178 


150 


150 


137.0 


125 


Five months 


170-180 


172 


155 


158.4 


140 


Six months 


180-200 


172 


160 


171.3 


160 


Seven months 




206 




185.4 


180 


Eight months 




206 




208.5 


200 


Nine months 




244 




226.2 
238.8 


225 


Ten months 




250 


Eleven months 




244 




242.0 


275 


One year 


300-400 


267 






290 


Two years 


600-750 











Feer. 53 Examinations of the cadaver show a smaller gas- 
tric capacity than that commonly accepted ; therefore it is not 
well to attempt to give to hand-fed children the maximum 
amounts which infants at the breast can take. The above table 
represents the average amount which babies at the breast will 
take. It should not be exceeded by children who are artificially 
fed. 

Pfaundler 225 considers that the gastric capacity must not 
be compared with the age or the weight of the infant, since 
children of the same age often vary much in the degree of 



DIGESTION. 65 

their development, and since the change in the child's weight 
does not run parallel with the steadily increasing capacity. 
The correct standard of comparison, according to this author, 
is the length of the child's body, or, more accurately, the length 
of the trunk. From the study of seventy cases Pfaundler 
draws these conclusions : 

I. The stomach of children at the breast is smaller than 
that of artificially fed infants. 

II. Healthy infant stomachs have a smaller real capacity 
than those diseased either organically or functionally. 

III. Large stomachs have little elasticity and distensibility, 
whereas the reverse is true of the small stomach. 

Pfaundler found not a single instance of dilated stomach 
in children who were breast-fed; in artificially fed infants 
he found dilatation in twenty per cent. 

We see, then, that the gastric capacity is a variable factor, 
depending on the rapidity of the child's growth, the kind of 
food administered, and the frequency of feeding. The figures 
of Feer and the measurements of Fleischmann, Beneke, and 
Frolowsky are high, and may be considered maximum amounts. 
The tables of Pfaundler, Holt, and Eotch probably represent 
the real capacity, while the figures based on measurements of 
the cadaver rather express the quantity of fluid which a fully 
distended or partially dilated stomach can hold. Since our 
knowledge of the anatomy of the infant's stomach teaches us 
that this organ readily dilates, and since clinical experience 
has shown that overfeeding (too large and too frequent meals) 
is only too common an occurrence, especially among artificially 
fed infants, the importance of carefully regulating the size 
and frequency of the meals cannot, in the light of our present 
knowledge, be overestimated. 

Gastric Digestion - . 
Marfan". 105 Gastric digestion is accomplished by the gastric 
juice, which is secreted by the gastric glands and is composed 



66 THE ARTIFICIAL FEEDING OF INFANTS. 

essentially of three substances : ( 1 ) lab-ferment, which coagu- 
lates the casein; (2) pepsin, a soluble ferment which renders 
the coagulum soluble and transforms it into peptone; (3) 
chlorine compounds, which unite with the casein in process 
of transformation, forming chloro-organic compounds analo- 
gous to amido-acids, and which can disengage free hydro- 
chloric acid when this transformation is near its end. In 
the healthy infant's stomach free hydrochloric acid is absent, 
or only present in small quantity. 

Casein is coagulated by the lab-ferment within fifteen min- 
utes of its entrance into the stomach. This ferment is present 
already formed in the infant's stomach, whereas in the adult 
it exists in the condition of a proferment (a substance analo- 
gous to propepsin), which is converted into lab in the presence 
of a feebly acid solution. Since at the beginning of digestion 
the reaction of the gastric juice is neutral or feebly alkaline, 
coagulation of the casein is not due to the presence of acids. 
All the casein is coagulated by the lab; then a portion is 
attacked by the combined chlorides and the pepsin, liquefied 
and transformed into peptone (caseone or caseose), which 
is directly absorbable; another portion passes in a clotted 
condition into the intestine, where its digestion is achieved 
by the pancreatic juice. On the other hand, Hammarsten and 
Arthus and Pages emphasize the differences existing between 
casein and albumin with regard both to their solubility and 
their digestibility. The action of lab is to separate the soluble 
albumin from the clotted casein with its lime-salt combination. 
The albumin can be taken up directly by the gastric and in- 
testinal mucous membrane (Briicke) and absorbed without 
undergoing further modifications; whereas the casein is di- 
gested principally in the intestine by the pancreatic secretions. 

The subject of milk coagulation in the stomach has recently 
been thoroughly investigated by Joseph Schnuker at the Caro- 
lina Children's Hospital in Vienna. 131 

According to this author, two forms of coagulation occur: 



DIGESTION. 67 

(1) so-called acid precipitation (Arthus and Pages), and 

(2) caseation or precipitation by lab-ferment (Arthus and 
Pages). 

1. Acid Precipitation. — In this case the casein does not exist 
as such, but in combination with lime. It only remains in this 
combination as long as there is present in the milk a mixture 
of mono- and di-phosphatic salts (especially sodium salts). 
When these salts are altered by the addition of some strong 
acid, a dissociation of the casein-lime combination occurs and 
the casein is precipitated. The clots resulting from acid co- 
agulation are very fine, soft, and flexible, easily soluble in weak 
alkaline fluids, and can be curdled again in this fluid by the 
lab-ferment. 

2. Caseation or Precipitation by Lab-Ferment. — In this pro- 
cess, according to Hammarsten, casein is split into two different 
forms of albumin, — paracasein and whey-albumin (called lacto- 
serum proteose by Arthus and Pages). 

This splitting up does not cause the precipitation of the 
paracasein, which first occurs when sufficient (from 0.02 to 
0.5 per cent.) earthy alkaline salts are present in the fluid 
(calcium chloride being the best). The paracasein is then 
set free from its insoluble casein-lime combination. Casea- 
tion occurs in coarse lumps taking the shape of the test-tube. 
After standing the whey exudes as a discolored fluid in which 
the whey-proteid is recognized by its failure to precipitate 
with heat and acid. It also gives the biuret reaction after the 
other soluble albumins of the milk-serum, lactalbumin and 
lacto-globulin, have been removed. Dry paracasein is with 
difficulty soluble in alkalies. Freshly caseated precipitated 
paracasein, however, can be dissolved easily in a weak am- 
monia solution; it can be precipitated out of such solution 
by soluble lime salts (under certain conditions of temperature, 
etc.) and also by sodium chloride whether lime salts are pres- 
ent or not, but paracasein cannot be precipitated by lab- 
ferment out of its neutral or faintly acid solution, even in the 



68 THE ARTIFICIAL FEEDING OF INFANTS 

presence of soluble lime salts. This is the most important 
distinction between acid-casein and paracasein (Hammarsten, 
Escherich, Arthns and Pages). 

The presence of lab-ferment and of paracasein has been 
demonstrated by Arthns and Pages in experiments on animals 
and with the stomach- tube in infants. 

Whether caseation occurs or not depends on the amount 
of acid present. The presence of lab-ferment as well as hydro- 
chloric acid in the stomach of the new-born infant has also 
been conclusively demonstrated by Szydlowsky, Schumburg, 
Boas, Johnson, Klemperer, Arthns and Pages, Kosenthal, and 
Leo. 

Biedert has shown that the fat of the milk acts by its en- 
closure in the lab clots so as to produce much finer curds, 
while Escherich finds that the fat, by hindering the spreading 
of the acid, delays its rapid action. The high degree of affinity 
of hydrochloric acid for cow's milk seems to be the reason 
why free hydrochloric acid appears late or not at all in the 
infant's stomach during digestion. 

Lindenan, Walther, Escherich, and Arthns and Pages agree 
that paracasein is more difficult of solution in the stomach than 
whe} r -albumin. It is also more resistant to pancreatic diges- 
tion, hence less well absorbed from the intestine (Escherich). 

Marfan. 105 We know by the test-tube experiments that the 
casein of cow's milk clots in large homogeneous masses which 
are rich in fat and must be of difficult digestion; mother's 
milk, on the other hand, coagulates in fine flakes, poor in fat, 
which are without doubt more accessible to the action of the 
gastric juice. If we remove the gastric contents from a nursing 
infant half an hour after the meal, we find that the chyme 
is almost completely liquid and filters easily, while at the end 
of three-quarters of an hour casein clots are still present in 
the stomach if the child is being fed on cow's milk. We may 
conclude, then, that woman's milk is digested almost entirely 
in the stomach, but cow's milk only partially. 



DIGESTION. 69 

Half an hour after a meal the gastric contents show the 
presence of peptones, whether the child be sick or healthy, 
and whether it be fed on woman's or cow's milk (Toch). The 
casein of cow's milk, which is a nucleo-albumin, is broken 
np by the digestive juices into proteoses and nuclein or pseudo- 
nuclein (paranuclein, according to Knopf elmacher, Wroblewsky, 
and Blauberg). During the course of digestion we find also 
ammoniacal compounds, leucin, tyrosin, and other by-products 
of albuminous digestion. Casein, then, is not only coagulated 
in the infant's stomach, but it is also liquefied and peptonized ; 
this second part of gastric digestion is much more complete 
when the infant is nourished at the breast than when cow's 
milk is given. 

The lactose undergoes in part lactic acid fermentation, and 
helps to bring about an acid reaction during the first fifteen 
or twenty minutes of digestion. The role of lactic acid in 
gastric digestion is not yet fully known; Biedert thinks that 
lactic acid can take the place of hydrochloric acid, of course 
less efficiently. Since the larger proportion of the hydrochloric 
acid unites with the casein and salts of the milk as fast as 
it is secreted, the presence of lactic acid (if this view be cor- 
rect) would seem beneficial for the infant. Zotow, 103 on 
the other hand, considers lactic acid fermentation a sign of 
dyspepsia, since he was never able to find lactic acid in the 
stomachs of healthy children. Soltau Fenwick holds the same 
opinion. 

It is supposed that the lactose not attacked by the microbes 
of lactic acid fermentation is absorbed as such, or is split up 
into glucose and galactose, which are directly absorbable. How 
this is accomplished is not yet definitely established, whether 
by the action of hydrochloric acid, or microbes, or of a special 
ferment (lactase). It is certain that the lactose is absorbed 
under one form or other almost entirely by the stomach; a 
minimal part is absorbed from the intestine. 

The greater portion of the salts is absorbed by the stomach, 



70 THE ARTIFICIAL FEEDING OF INFANTS. 

besides most of the water taken into the economy; von Mering 
alone asserts that the latter passes altogether into the intes- 
tine. The fats are not modified in the stomach; they enter 
the intestine either free or imprisoned in the casein clots. 

We can divide gastric digestion into three phases. In the 
first, which lasts about half an hour, the lab-ferment coagulates 
the casein in the presence of a neutral or alkaline reaction. 
In the second the reaction of the chyme becomes acid; lactic 
acid is formed, and the casein unites with the chlorides of the 
gastric juice; in the third phase the stomach is emptied by 
peristalsis; then and then only do we find the reactions de- 
noting the presence of free hydrochloric acid. 

Hayem and Winter 105 made a special study of the chemistry 
of the gastric juice in infants. They conclude that : 

1. The total acidity is feeble; it is due to lactic acid, and 
especially to hydrochloric acid in combination with organic 
matters and ammonia. 

2. The total chlorides are small in quantity, which indicates 
either that the secretory apparatus is but slightly developed 
in the infant or that there is only a feeble response to the 
stimulus of milk entering the stomach. 

3. After half an hour the digestion of a test-meal is about 
as advanced as it would be in the adult after one hour. 

Marcel and Henry Labbe 108 have shown that : 

1. In infants under two years the gastric juice never con- 
tains free hydrochloric acid during digestion. 

2. The fixed chlorides exist in quite definite proportions; 
their quantity increases rapidly during the first months of 
life, to attain a maximum at one year and then decrease. 

3. The combined chlorides and the total chlorides increase 
with the age of the child. 

4. The total acidity, feeble in the new-born, increases very 
rapidly during the first months of life, owing to fermentation 
in the stomach ; later it increases more slowly parallel with the 
combined chlorides. 



DIGESTION. 71 

Marfan. 105 We find a higher total acidity when healthy 
infants are fed on pure cow's milk; this acidity is due not 
to free hydrochloric acid, but to lactic acid (which is formed 
in greater abundance than when the infant is fed on mother's 
milk) and to combined chlorides, which are also present in 
larger quantities. The percentage of total chlorides is also 
higher; it reaches a figure at the end of three-quarters of an 
hour almost equal to that in the adult one hour after the test- 
meal. But the ratio of the total chlorides to the fixed chlorides 
is rather inconstant, sometimes higher and sometimes lower, 
indicating anomalies in the gastric chemistry which are in 
accord with the exaggerated elevation of *• ■ = — ^- . A = the 
degree of total acidity ; H = free hydrochloric acid ; C = the 
combined chlorides. The elevation of a indicates an excess 
of acids of fermentation. These characteristics can be con- 
sidered as the effect of a certain degree of gastritis with rela- 
tive hyperpepsia and abnormal fermentations. 

All authors are agreed in recognizing that free hydrochloric 
acid is absent from the chyme during gastric digestion of milk, 
whether the infant be sick or healthy; but there is disagree- 
ment on the question whether hydrochloric acid does not ap- 
pear towards the end of digestion or after the evacuation of 
the stomach contents. According to Eeichmann, Leo, Cassel 
and Heubner, Wohlmann, and A. Czerny, hydrochloric acid ap- 
pears near the end of digestion or after the evacuation of the 
stomach contents. In breast-fed babies A. Czerny found hydro- 
chloric acid in the stomach one and a quarter hours after taking 
food, to attain its maximum in from one and a half to two 
hours afterwards; in the artificially fed child hydrochloric 
acid appeared only about two hours after the meal. Einhorn 
and Hayem found no free hydrochloric acid. Thiercelin did 
not find free hydrochloric acid in healthy infants; it was, 
however, occasionally present in dyspeptic children. 

The absence of free hydrochloric acid is explained by the 
fact that during digestion a large portion of it enters into 



72 THE ARTIFICIAL FEEDING OF INFANTS. 

combination with the casein and phosphatic salts of the milk; 
this also shows why its appearance is longer delayed in the 
digestion of cow's milk. 

Lactic acid is present during the first half-honr of digestion, 
and after that time hydrochloric acid (Uffelmann, Ewald, 
Boas). Henbner has estimated the quantity of lactic acid 
present to be from 0.10 to 0.40 per cent. 

Bauer and Deutsch 17 have investigated the gastric secre- 
tions in a large number of children. Of these eight were in- 
fants, five under five months, three over five months old, — 
all of them healthy. The latter were fed on pure cow's milk, the 
former on pure cow's milk and water, equal parts. In from 
three-quarters of an hour to one hour and a half after food 
ingestion lactic acid was always found in large amounts; the 
total acidity was feeble. Free hydrochloric acid could not be 
demonstrated in the younger infants. In the three cases 
over five months of age they obtained from 0.06205 to 
0.08395 per cent, free hydrochloric acid after from one 
and a half to two hours. They conclude that during the 
first months of life lactic acid predominates, especially at the 
beginning of digestion. During the second half of the first 
year the percentage of free hydrochloric acid increases and is 
approximately similar to that found in adults. The reaction 
of the empty stomach was found to be neutral or acid, the 
presence of secretion being due to irritation by the stomach- 
tube. The specific gravity of the gastric juice varied from 
1005 to 1009. Experiments were made to determine the power 
and rapidity of absorption by the stomach. Potassium iodide 
was detected in the saliva in from four to seven minutes after 
its ingestion, and in the urine in from seven to fifteen min- 
utes, somewhat earlier than is the case in adults, while the 
salol test gave positive results usually in from thirty to thirty- 
five minutes. Butyric and acetic acids could not be demon- 
strated. 

The gastric secretions of three premature infants were also 



DIGESTION. 73 

studied ; only minimal amounts of acid could be demonstrated. 
Lactic acid was always present, but free hydrochloric acid was 
not demonstrable. Wohlmann obtained similar results. 

Mne healthy children, varying in age from two and a half 
to ten years, showed in the great majority of the cases the 
presence of free hydrochloric acid from one to one and a half 
hours after taking food; the quantity varied from 0.04015 
to 0.12957 per cent. At the beginning of digestion lactic acid 
predominated, later hydrochloric acid. There was a marked 
antagonism between hydrochloric and lactic acids. The motor 
power and power of absorption of the stomach showed little 
variation from the conditions present in the adult. Lactic acid 
was found ten minutes after taking food; it increased in 
quantity during the next thirty to forty minutes, to dis- 
appear gradually with the appearance of hydrochloric acid. 
We have, then, three stages of digestion: (1) lactic acid alone, 
(2) lactic and hydrochloric acids both present, (3) hydro- 
chloric acid alone. 

In infants suffering from gastro-intestinal disorders the 
presence of free hydrochloric acid could not be demonstrated. 
Lactic and butyric acids were found in considerable, and acetic 
acid occasionally in smaller, quantity. Where the disease was 
confined to the intestines, free hydrochloric acid was sometimes 
present. Motility and absorption were much delayed. 

Cohn investigated for the presence of free hydrochloric acid 
by Mintz's method in eighty cases ; all of them were breast-fed 
and suffering from a variety of gastro-intestinal disturbances, 
of which eleven were acute and sixty-nine subacute and chronic 
disorders. Free hydrochloric acid could be demonstrated in 
only fourteen out of ninety-four investigations; the largest 
quantities found were 0.13, 0.1, and 0.062 per cent. The tests 
were carried out one and a half, two, and two and a half hours 
after nursing. 

Wolf and Fried jung 15t have studied the secretions of the 
stomach in ninety-eight cases, varying in age from ten days 



74 THE ARTIFICIAL FEEDING OF INFANTS. 

to twenty-one months, and suffering from various acute and 
chronic gastro-intestinal diseases. They conclude that the 
presence or absence of the normal secretions of the stomach 
is not a reliable test of the powers of digestion. 

Bauer and Deutsch. 17 The views of authors are consider- 
ably at variance with regard to the kind of acid predominating 
in the infant's stomach during digestion. Biedert, Wohlmann, 
Moncorvo, and others consider hydrochloric acid the domi- 
nating factor ; on the other hand, Heubner, Van Puteren, Mas- 
sing and others emphasize the presence of lactic acid. Gener- 
ally they found hydrochloric acid present only in isolated cases ; 
this must be ascribed (in accordance with Leo's statement) 
to the power of milk to combine with and neutralize acids. 

Leo obtained a faintly acid reaction one-quarter of an hour 
after milk was ingested ; at the end of digestion a small amount 
of free hydrochloric acid could sometimes be demonstrated. 
Van Puteren found after ten minutes' digestion a total acidity 
of 0.878 per cent., with maximum values of from one to 2.1 
per cent. Von Jaksch, in a three-weeks-old infant, found a 
total acidity of 0.512 per cent, after one hour's digestion. 
Einhorn obtained an acid reaction after one hour, but could 
not demonstrate the presence of free hydrochloric acid. Heub- 
ner was able to determine quantitatively the presence of free 
hydrochloric acid after from one and a half to two hours' 
digestion in the great majority of his observations; in a less 
advanced stage of digestion he almost invariably found lactic 
acid present. Copolt determined the presence of free hydro- 
chloric acid only exceptionally; in contrast to this, he found 
the total acidity to vary from 0.02 to 0.08 per cent. On the 
other hand, Wohlmann's figures for free hydrochloric acid are 
high. He found from 0.831 to 1.08 per cent, present in from 
one and a quarter to two hours after taking food. Marcel and 
Henry Labbe obtained the following figures at different ages, 
representing the degree of total acidity: in the new-born 0.03 
per cent.; from one to six months 0.11 per cent.; from six 



DIGESTION. 75 

months to one year 0.13 per cent.; from one to two years 0.14 
per cent. 

W. Soltau Fenwick 52 instituted a series of experiments on 
healthy infants, some breast-fed, others getting cow's milk or 
farinaceous food. The tests were identical in method and the 
same quantity of food was given each time. 

I. The amount of hydrochloric acid secreted varies in differ- 
ent children and in the same child from day to day and from 
meal to meal. In the stomach of nursing infants milk is 
usually curdled in from ten to fifteen minutes after its en- 
trance, owing to the presence of lab-ferment in the gastric 
secretion. This is observed immediately after birth. The acid- 
ity of the gastric contents gradually increases during digestion, 
and attains its maximum in from ninety to one hundred and 
ten minutes after the commencement of the meal. The average 
total acidity is 0.02 per cent, at the end of ten minutes, 
from 0.06 to 0.075 per cent, at the end of one hour, and 0.13 
per cent, at the end of eighty minutes. (KB. — Ordinary 
methods of filtration reduce the acidity of the gastric contents, 
often by as much as 0.05 per cent.) Free hydrochloric acid 
is an inconstant factor, appearing usually after eighty minutes, 
or when the viscus is partially empty. Pepsin is invariably 
present so long as the secretion contains any trace of the min- 
eral acids. Lactic and other secondary acids are not found 
in normal digestion, and must be regarded as evidence of 
fermentation. 

II. When the infant is fed on cow's milk the total gastric 
acidity is greater, and may amount at the end of eighty min- 
utes to 0.18 per cent, of hydrochloric acid. Free hydrochloric 
acid can usually be found near the end of digestion. In most 
cases lactic acid can also be detected, but never in any ap- 
preciable amount. 

III. When the diet is farinaceous, the total acidity of the 
gastric contents is invariably diminished, and may not exceed 
more than half the normal. In a few cases eighty minutes 



76 THE ARTIFICIAL FEEDING OF INFANTS. 

after giving oatmeal and water there was only faint acidity. 
The same children showed normal powers of secretion when 
given milk. 

The quantity of gastric juice secreted bears a distinct rela- 
tion to the kind of food and the size of the meal. The proteid 
elements of the milk seize on the free acids and fix them in a 
chemical combination. Pfungen has shown that one hundred 
grammes of milk can saturate 0.298 gramme of hydrochloric 
acid; Liittke, that this combination is stable at high tempera- 
tures, and does not give the usual reaction of free acid. Free 
acid is not found until all the proteids have been saturated, 
hence appears late or not at all. Bacterial growth is thus not 
inhibited to any extent. Fenwick found that the stomach 
emptied itself at the end of one and a half hours (on the 
average) in breast-fed children and in those fed on cow's milk 
at the end of two and a quarter hours; in all cases the major 
portion of its contents disappeared within the first hour. 
About forty-five minutes longer were required to dispose of 
the last thirty to forty cubic centimetres. Peptone can always 
be recognized within half an hour of the ingestion of food, 
proving the stomach to be more than a mere reservoir. 

After the food leaves the stomach there still remains a small 
amount of mucus and gastric juice, in which free hydrochloric 
acid can be recognized. Pfannenstill has shown by the salol 
test that the motor activity of the stomach is not less than in 
older children. Salicyluric acid appears in the urine within 
the normal time. 

Summary. 

It would appear from these rather discordant observations 
that during the early months of life the secretions of the 
stomach — namely, those of hydrochloric acid and pepsin — are 
deficient in quantity when compared with those of a healthy 
adult. Lab-ferment seems, as a rule, to be present in sufficient 
amount, but the hydrochloric acid combines with the albu- 
minoids of the milk as fast as it is poured out, so that it is 



DIGESTION. 77 

only at the end of digestion, if at all, that we find free hydro- 
chloric acid. Lactic acid, on the other hand, is present almost 
from the first, owing to the splitting np of the lactose furnished 
in the nourishment. While the secretion of hydrochloric acid 
seems to be sufficiently plentiful for the needs of the healthy 
breast-fed infant, it would seem that the artificially fed child 
requires more hydrochloric acid for the purposes of digestion, 
owing either to the greater saturating power for acids of the 
casein of cow's milk or to the greater preponderance of the 
albuminoids in the latter. Hence comes the greater frequency 
of gastric fermentation in bottle-fed babies, since the normal 
bactericidal action of the hydrochloric acid is feeble or absent. 
No standard can be formulated for the amount of free hy- 
drochloric acid present normally during digestion; but it 
must be accepted as established that free hydrochloric acid 
is an inconstant factor, rarely found in considerable quantity. 
Lactic acid fermentation seems to be a part of normal diges- 
tion. 

Marfan - . 105 The time of gastric digestion varies in different 
subjects and according to the kind of food given. Generally 
it may be said that in the healthy nursing child the stomach 
is emptied from one and a half to two hours after the meal; 
if the child is fed on boiled or sterilized cow's milk the time 
required will be from two to three hours; while raw cow's 
milk does not leave the stomach until four hours after its 
administration, according to Eeichmann. 

The muscular wall of the stomach is relatively thin during 
the early months of life and peristaltic movements are doubt- 
less feeble in the new-born. But woman's milk, after the 
coagulation of the casein, remains almost liquid; it can be 
digested without being churned in the stomach ; it is evacuated 
the more easily into the intestine since it is assisted by gravity, 
the position of the stomach being nearly vertical. When the 
child is nourished with cow's milk, the volume of the clots 
must increase the difficulty of peristalsis. This is doubtless 



78 THE ARTIFICIAL FEEDING OF INFANTS. 

one of the causes of the tardy and imperfect digestion of 
cow's milk by the infant. 

Intestinal Digestion. 
The water which has not been absorbed by the stomach en- 
ters the duodenum in successive jets mixed with the mucus 
of the chyme. The casein leaves the stomach partly in the 
form of small clots but slightly modified, partly as syntonin, 
propeptone, peptones, besides compounds of chlorine and am- 
monia, fatty acids, leucin, tyrosin, and gases (chiefly carbon 
dioxide). Only a small amount of lactose enters the intes- 
tine; part of it has been absorbed from the stomach; proba- 
bly part passes into the intestine as lactic acid. The fat is 
not modified as it leaves the stomach; a part is in suspension 
in the fluid, a part is incorporated in the casein clots. The 
salts which are not in solution are probably for the most part 
incorporated in the casein clots. The whole has an acid re- 
action as it enters the duodenum, where it is subjected to the 
action of the bile, the pancreatic, and the intestinal juices. 

Anatomy oe the Intestinal Tract. 
Normally, the abdomen of the infant is rather prominent 
and voluminous; besides this, the lumbar spine is almost 
straight and not curved as in the adult (Marfan). The length 
of the intestinal canal is more than six times that of the 
body. Frolowsky states that the relative length of the large 
as compared with the small intestine equals in the new-born 
one to six, in infants one to five, and in the adult one to four. 
The muscular coat of the intestines is relatively poorly de- 
veloped, peristalsis is irregular and inclined to be sluggish, 
and there is a tendency to dilatation of the abdomen (Monti). 
The duodenum forms a ring instead of the horseshoe curve 
of adult life (Marfan). It is proportionately longer than in 
adults, and its second portion constitutes a reservoir in which 
the bile and pancreatic juices can accumulate. The caecum 



DIGESTION. 79 

lies high in the abdomen. The sigmoid flexure is very long, 
representing at birth nearly half the large intestine; it is 
very sinuous, and lies almost altogether outside the very nar- 
row pelvic cavity. 105 We note in the anatomy of the intes- 
tines : the feeble development of the muscular wall, the rela- 
tively advanced development of the mucosa, especially of the 
lymphoid elements, the great vascularity of the villi, and the 
richness in nerves imperfectly myelinized. 105 Lieberkuhn's 
glands are less numerous than in the adult ; the mucous glands, 
on the contrary, are very plentiful and their secretion is copi- 
ous." Brunner's glands, though numerous, are in the early 
stage of their development. 105 

The development and vascularity of the villi and the almost 
complete evolution of the lymphatic tissues furnish conditions 
favorable for the absorption of clryle. Since the secretory 
apparatus is less developed, the food must be easy of di- 
gestion. The characteristics of the nervous tissues explain 
the readiness with which the intestines respond to causes of 
irritation and the ease with which this excitability becomes 
exhausted. 105 

Baginsky considers that the connective-tissue corpuscles of 
the mucosa form part of the lacteal system which begins at 
the terminal processes of the papillae ; they constitute, together 
with the large lymph-paths of the intestine, the real absorbent 
system (Baginsky). Histological investigation has shown that 
the absorptive power of the intestinal tract in infancy is essen- 
tially greater and more developed than that of adults, but phys- 
iological and chemical activity is less than in those of mature 
age because the glands are relatively poorly developed. On 
account of the extent and development of the absorbent lymph- 
paths, the intestine of the infant will easily absorb all the 
nutrient material which can be taken up without marked chemi- 
cal change, whereas all food products which require marked 
chemical alteration can be utilized but slightly, if at all (Ba- 
ginsky). 



80 THE ARTIFICIAL FEEDING OF INFANTS. 

Marfan. 105 At birth the pancreas possesses its normal form 
and structure; its size is considerable; it weighs thirty-two 
grammes, — that is to say, 1 ^ part of the weight of the body ; 
whereas in the adult it weighs from eighty to one hundred 
grammes, — that is to say, about -g-J-g- part of the body weight. 
The pancreatic juice contains three ferments: trypsin, which 
in an alkaline medium transforms albuminoids into peptones; 
ptyalin or amylopsin, which saccharifies starch; and steapsin, 
which emulsifies the fats. Trypsin is present from birth and 
even during foetal life (Albertoni, Langendorff, Hammarsten), 
but its secretion is scanty in the first weeks. Steapsin is also 
present from the first; not so the saccharifying ferment. 

According to Korowin, amylopsin is absent up to the twen- 
tieth day, and only traces are present till the fourth month; 
from the sixth month the saccharifying power is definitely 
established. Zweifel found the pancreatic extract without 
power to act on starch up to the eighteenth day; Krueger 
obtained similar results in experiments on new-born animals. 
E. Moro claims to have found traces of the saccharifying fer- 
ment in the pancreas of the new-born. We may conclude that 
this ferment is absent or exists only in very small quantities 
during the first period of the infant's life. Since milk con- 
tains no starch, the young child has no need of this ferment; 
but one can readily understand the dangers of administering 
starchy foods to infants before the close of the first year. 
Zweifel states that in robust infants the trypsin ferment can 
digest albuminoids even in the first month; the power to 
split up neutral fats exists, however, only to a slight degree 
in infancy. 

The liver is more voluminous than in the adult. 

Bile forms the larger part of the meconium, and is present 
from the third month of foetal life. The total quantity of 
bile secreted by the new-born and the infant is relatively more 
considerable than the amount secreted by the adult. During 
infancy the bile is deficient in fat, organic salts, and choles- 



DIGESTION. 81 

terin, and especially poor in biliary acids (Jacubowitsch, con- 
firmed by Baginsky and Sommerfeld) ; mineral salts, except 
iron, are present in small amounts; bilirubin and biliverdin 
are abundant. 

Bile does not seem to have any powerful influence on di- 
gestion, but it helps to hold the fats in emulsion. Its anti- 
septic power is feeble. The deficiency in biliary acids explains 
the inability of the infant to digest food too rich in fat, also 
the ease with which bacterial growth and intestinal putrefaction 
occur (if the other conditions are favorable). 

Baginsky thinks that the deficiency in biliary acids favors 
pancreatic digestion, since the latter will not occur in too acid a 
medium. In the intestine cholesterin is neither absorbed nor 
modified, but is eliminated as such by the faeces. The biliary 
salts are decomposed in the intestine into amido-acids (taurin 
and glycocol) and a cholic nucleus (base). The former are re- 
absorbed almost entirely and returned to the liver ; the latter is 
in part reabsorbed and in part eliminated by the faeces. Mi- 
crobes probably are responsible for the splitting up of the bile 
salts, for in the intestine of the foetus where germs are absent 
we find unaltered taurocholic acid (Zweifel). In the meco- 
nium before birth the normal biliary pigments are found in 
an unaltered condition, also a red pigment due to oxidation 
(Zweifel). In the intestine of the new-born and nursing in- 
fant there is only partial reduction of the normal pigments, 
so that we find at the same time bilirubin and hydro-bilirubin. 
In pathological conditions the stools contain a further product 
of oxidation, — namely, biliverdin (green stools). 

The secretion of the intestinal glands is alkaline and pos- 
sesses only feeble digestive properties. Its principal function 
is to alkalize the chyle and thus further absorption and in- 
crease peristalsis. Miura has found in the intestine of the 
foetus and the new-born a ferment capable of converting cane- 
sugar; other authors claim to have discovered a saccharifying 
ferment, — namely, lactase. Moro discovered a diastatic enzyme 

6 



82 THE ARTIFICIAL FEEDING OF INFANTS. 

which was present in the intestinal contents and in the faeces, 
as a rule, directly after birth ; during the first weeks of life 
it increased rapidly in quantity. This diastatic enzyme is 
secreted by the glandular organs of the intestine, and traces 
of the same can be demonstrated in the extract of pancreas 
of the new-born. Bacteria, on the other hand, have no share 
in its production. Woman's milk normally contains an enzyme 
of intense saccharifying properties, which is not present in 
cow's milk. This enzyme can be found in the faeces of nursing 
infants, and considerably increases their diastatic properties. 
Marfan has found a fat-splitting ferment (lipase) in mother's 
milk, which is very active. It is also present in cow's milk, 
but is less active. 

When infants are nursed at the breast, the gastric chyme 
reaches the duodenum with portions of the casein transformed ; 
its acidity is feeble, and the undigested clots are very fine, so 
that trypsin can act rapidly and easily. This ferment liquefies 
the coagulated casein and converts it into anti-peptone, which 
is absorbed as such, and hemi-peptone, which after prolonged 
pancreatic digestion is broken up into amido-acids (leucin, 
tyrosin, and hypoxanthine) and other by-products. When in- 
fants are fed on cow's milk, the digestion of casein in the 
stomach is much less advanced. The chyme is more acid and 
the clots larger and more difficult of penetration, so that the 
pancreatic digestion of the albuminoids is slow and imperfect. 

Lactose enters the intestine partly as such, partly as lactic 
acid. The lactose may be absorbed as such, or may be split 
up by the action of micro-organisms into galactose and glu- 
cose, which can be directly absorbed. Others think that lactase 
is responsible for this change. Undoubtedly a portion of the 
lactose undergoes lactic acid fermentation in the intestines. 
When the fat reaches the intestines, part of it is free and a 
part is imprisoned in the casein clots and is freed from them 
by the action of trypsin. A small portion of the fat is split 
up into fatty acids and glycerin; the fatty acids combine with 



DIGESTION. 83 

the alkalies of the digestive juices to form soaps. This saponi- 
fication, which is only feeble, has long been attributed k> steap- 
sin, but seems really to be due to the action of microbes. The 
sole function of the steapsin is to emulsify fats ; emulsification 
is favored by the natural viscosity and alkalinity of the pan- 
creatic juices, also by the presence of soaps and free fatty 
acids. The fat which is emulsified in very fine droplets is 
absorbed directly by the lacteals of the villi; the remainder 
traverses the intestine, undergoing natural saponification and 
microbic fermentation. In a healthy infant fed on mother's 
milk, rapidity is the distinguishing trait of intestinal diges- 
tion. After the passage of the chyme into the duodenum, its 
digestion is almost complete. Absorption takes place actively 
in the upper part of the small intestines, especially of the 
albuminoids, so that normally we find few traces of the latter 
in the lower part of the intestinal tract. 

Senator considers that this rapid digestion and absorption 
explains the slight degree of intestinal putrefaction when the 
child is fed on breast-milk. We also know that the duodenum 
contains the fewest microbes ; lower down, where they are more 
numerous, they do not find putrescible albuminoids to act upon. 
After the absorption of the food-stuffs the chyle consists prin- 
cipally of the following substances : biliary residues, whose 
destiny we know; amido-acids, various acids due to microbic 
fermentation; soaps, — products which are partly absorbed by 
the portal vein and transformed by the liver (thus leucin and 
tyrosin are changed into urea) and partly eliminated by the 
faeces; and a small quantity of neutral fats and acids which 
are passed with the stools. 

With all this there still remain portions of the food sub- 
stance not digested, which, with the other residues, are the 
prey of microbes and give rise to products of putrefaction, 
indol, skatol, phenol, ammoniac, and various toxins, which 
are also partially absorbed and transformed by the liver and 
partly eliminated by the fasces. The phenomena of putre- 



84 THE ARTIFICIAL FEEDING OF INFANTS. 

faction attain their maximum in the large intestine, but nor- 
mally they are never very considerable: witness the small 
amount of gas in the colon and the absence of fecal odor in 
the stools. 

Summary. 

Casein is only partially digested in the stomach, especially 
when cow's milk is the child's food. Pancreatic digestion plays 
the chief role in finally converting the casein into a form in 
which it can be absorbed by the duodenum and jejunum. 
Owing to the small amount of the gastric and the pancreatic 
secretions, the digestion of the proteids of milk (especially of 
cow's milk) is often imperfectly carried out during the first 
months of life. In the healthy breast-fed child the proteid 
residue is small and intestinal putrefaction is not a marked 
feature of digestion. The power to split up neutral fats is 
feeble during the first months of life; so also is the power 
to digest starch. Normally, a considerable portion of the fat 
is excreted in the stools. Milk-sugar is readily digested by the 
infant and normally leaves little residue. It seems probable, 
in the light of recent investigations, that the enzymes which 
have been found in the intestinal secretions and in mother's 
milk play a not inconsiderable role in the infant's digestive 
processes. 

Experiments in Artificial Digestion. 

The following conclusions were reached by J. H. Coriat 206 
and A. S. Warthin 152 after a series of experiments with 
rennin : 

1. Casein can be digested by both pepsin and pancreatin 
without being first coagulated by rennet. 2. When rennin is 
also present the amount of digested proteid or albumose proteid 
produced by the proteolytic enzymes is greater in every case. 
3. The presence of rennin is necessary to secure a more rapid 
and energetic casein digestion. 4. The increased peptone pro- 
duction due to the presence of rennin takes place in both 
acid (pepsin) and alkaline (trypsin) media. 5. Only when 



DIGESTION. 85 

combined hydrochloric acid exceeds one-tenth of the bulk of 
the milk used will it coagulate milk, but not as rapidly as 
free hydrochloric acid. 6. Eennin coagulates milk without 
hydrochloric acid; but when the latter is present in combined 
form, and equal to one-tenth or less of the bulk of the milk 
used, coagulation takes place in a much shorter period of time. 
7. The presence of acid-albumin hastens coagulation by the 
enzymes. 8. The time of coagulation decreases steadily as 
greater amounts of absolute rennin are present. 9. Vegetable 
enzymes coagulate milk in a way which compares favorably 
with rennin, and coagulation takes place under the same con- 
ditions as to temperature, acidity, and quantity present as 
rennin. 10. Enzymes exist in the plant kingdom which have 
an action analogous to that of rennin. 

Rennet. 
Richmond. 121 Bennet acts on casein only in neutral or acid 
solution. The optimum temperature is 41° C. (105° F.), the 
curd being firm. At a low temperature (15° to 20° C.) the 
curd is quite soft and floceulent, and at 50° C. the curd be- 
comes very soft. The larger the amount of acid present the 
greater is the rapidity of its action on milk. The addition of 
water to milk causes it to be acted upon more slowly by rennet 
and the curd is less firm. By heating milk the action of rennet 
is delayed, owing to the removal of some of the soluble calcium 
compounds. By adding soluble lime salts the milk will be 
curdled in the usual manner. 

Excretion. 
Defecation. 105 — In the new-born and in the infant the mus- 
cular wall of the intestine is poorly developed and peristaltic 
movements are feeble. Zweifel has remarked that in the foetus 
the intestinal contents move with extreme slowness ; in a foetus 
of three months the ileum and colon are empty; it is only at 
the end of the fourth month that the caecum contains meco- 



86 THE ARTIFICIAL FEEDING OF INFANTS. 

nium; the colon does not contain meconium before the fifth 
month. 

After birth, when food is introduced and the secretion of 
the digestive juices becomes established, peristalsis becomes 
more active ; the progress of food through the intestinal tract, 
however, is due perhaps more to a certain vis a tergo than to the 
influence of the still feeble peristaltic movements. It has been 
calculated that the chyle takes six hours to traverse the intes- 
tinal tract. 

A healthy child usually has three or four evacuations daily 
during the first month of life, two or three a day for the next 
five or six months, and one or two a day during the remainder 
of the first year and the second year. Divers causes contribute 
to bring about this frequency in the evacuations. The prin- 
cipal factors are the large number of meals, the relative abun- 
dance of food, and the resulting relatively more considerable 
proportion of fecal material. Other factors are the semi-liquid 
state of the faeces and the feebleness of the anal sphincter. 
We must not forget that while the muscular coat of the intes- 
tine is little developed at birth, its reflex excitability is greater 
in the new-born and in the infant, since the still imperfectly 
developed cerebrum does not restrain the functions of the cord, 
whose evolution is more advanced. 

The meconium may be brown, green, or black in color. It 
consists principally of epithelial cells from the intestinal mu- 
cosa, mucus and biliary secretions and pigments, chlorides and 
alkaline sulphates, a very small amount of phosphates and a 
minimal amount of iron (Guillemonat), leucocytes, choles- 
terin and haematoidin crystals, and grayish and fatty granula- 
tions (debris), probably from the amniotic fluid swallowed. 
There is none of the habitual products of putrefaction until post- 
natal infection has occurred. Meconium is usually evacuated 
within from six to twelve hours after birth, and is absent after 
the first two or three days. The total amount averages seventy- 
two grammes (Depaul). 



DIGESTION. 87 

The amount of faeces excreted by the infant is greater in 
proportion to the body weight than in the adult, on account 
of the relatively greater amount of nourishment which the 
former takes. According to Uffelmann, an infant at the breast 
excretes daily three grammes for each kilogramme of body 
weight, — about three per cent, of the nourishment taken; 
whereas the infant fed on cow's milk excretes from four to 
five per cent, daily (Monti). 

Michel 105 found that an infant at the breast less than one 
month of age, and taking half a litre of milk a day, expelled 
daily, on the average, fifteen grammes of liquid fasces or three 
grammes of dried faeces. In the succeeding months this can 
rise to eighty grammes. The adult passes, on the average, 
one hundred and seventy grammes daily. 

Towards the end of the first week the stools of the healthy 
breast-fed infant become of normal golden color; up to that 
time they have a greenish tinge. Even under normal condi- 
tions the faeces of healthy children contain at times yellowish- 
white masses. These do not consist of casein, as used to be 
thought, but are mainly made up of fat. Their consistence is 
that of a soft, semi-liquid paste, which, while it is favorable 
for absorption, also renders autointoxication more easy. The 
odor of the stools is not distinctly fecal, but resembles that of 
sour milk, and is not especially offensive. In healthy breast-fed 
infants the reaction of the stools is feebly acid, due to the 
presence of lactic and acetic, perhaps also butyric and valeric 
acids, which come from the fermentation of lactose. These 
acids must exist in considerable amount, since they are capable 
of neutralizing the alkalinity of the normal intestinal secre- 
tions. It has been suggested that they prevent the putrefaction 
of albuminoid substances. 

In the new-born infant the pigment of the faeces consists 
principally of bilirubin. Wegscheider has found traces of 
urobilin (hydro-bilirubin), though Zweifel and Hoppe-Seyler 
deny its presence. Wegscheider found at times biliverdin 



88 THE ARTIFICIAL FEEDING OF INFANTS. 

(Monti). Blauberg 13 also found both urobilin and biliverdin. 
He states that the stools may acquire a green color ( due to bili- 
verdin) after exposure to the air for some time. On the other 
hand, Pfeiffer rejects ZweifeFs view that increased acid for- 
mation or the atmospheric oxygen gives rise to this greenish 
color, and considers that alkalinity which is furthered by bac- 
terial development is responsible for it. Hayem and others 
have found bacilli which produce a green color. Blauberg 
thinks that not improbably ferments share in producing it.* 

Marfan. 105 Infants' stools contain from eighty to eighty-five 
per cent, of water (Blauberg gives from seventy-five to eighty- 
five per cent.). The dry residue consists of food remnants, 
intestinal secretions, and bacteria. Faint traces of peptone are 
present (Blauberg, Wegscheider, Uffelmann). 

Uffelmann has maintained, in opposition to Wegscheider, 
that at times leucin and tyrosin are found. The absence of 
products of putrefaction in normal digestion helps to explain 
the feeble toxicity of the faeces (Bouchard) . Indol is ordinarily 
absent, but it may be present, as well as skatol and phenol 
(Uffelmann, Blauberg). Oxy acids are always present (Winter- 
nitz, Blauberg). Blauberg finds that small amounts of lactose 
are present during the first week of life. Marfan, on the other 
hand, states that there are no traces of sugar in the faeces, but 
merely the products of fermentation of lactose, especially lactic, 
acetic, butyric, and valeric acids. The presence of acetic acid 
seems highly probable (Blauberg), since Baginsky has demon- 
strated that lactose is decomposed in the intestine into acetic 



* The analyses of faeces published by Wegscheider in 1875, in his 
treatise " On the Normal Digestion of the Infant," were as follows : 
one hundred parts of faeces contain: water, 83.13 per cent., organic 
matter 13.71 per cent., salts 1.16 per cent. Ten analyses of the solids 
gave 3.39 per cent, for mucin, epithelial debris, and lime salts, aque- 
ous extractives 5.35 per cent., alcoholic extracts 0.82 per cent., choles- 
terin 0.32 per cent., mineral salts 1.36 per cent., fat and fatty acids 
1.44 per cent. 



DIGESTION 89 

and carbonic acids, methane, and water. The small amount of 
gas in the intestines is almost odorless, or smells weakly of 
butyric acid. It consists of carbon dioxide, nitrogen, hydrogen, 
and methane. 

Fat constitutes the major part of the infant's faeces. It is 
present as globules of neutral fat, crystals of the fatty acids, 
and especially lime soaps (oleate, palmitate, and stearate of 
lime). The amount of fat in the dried stools varies much, 
according to different investigators. Wegscheider placed it 
at from nine to twelve per cent., Biedert at ten to twenty per 
cent., Bendix at fourteen to twenty per cent., while Heubner 
considers twenty-five per cent, the maximum. Tschernow 
gives twenty to thirty per cent, and Michel twenty per cent, 
as the average. The large amount of fat not assimilated is 
remarkable. It would certainly seem as if the presence of an 
excess of fat, of which only a part is absorbed, is essential 
for the normal digestion of mother's milk. 

Blauberg found for the first week of life that the mineral 
substances amounted to thirteen and a half per cent, of the 
dried faeces. About half of these are soluble in dilute hydro- 
chloric acid. 

The lime salts amount, on the average, to 15.31 per cent, 
of the soluble ash. The phosphoric acid varies from ten to 
thirteen and a half per cent. Considerable amounts of lime 
are in combination with organic acids. 

According to Uffelmann, from twenty-nine to thirty-one per 
cent, of the fecal ash and ten per cent, of the dried residue 
consist of lime, besides which potash, soda, chlorine, and sul- 
phuric and phosphoric acids are present. A portion of these 
minerals was originally present as carbonates and soaps. 

Uffelmann 161 investigated the faeces of nine children, all at 
the breast and getting no other food, varying in age from one 
week to one year. He found a small amount of albuminoids, 
fat, free fatty acids, soaps (especially earthy soaps), potash, 
soda, lime, magnesia, and iron salts, united to hydrochloric, 



90 THE ARTIFICIAL FEEDING OF INFANTS. 

sulphuric, and phosphoric acids, and organic acids, besides 
mucus, epithelia, cocci and bacilli, hay bacilli, biliary coloring 
matter (altered and unaltered), cholalic acid, cholesterin, and 
at times leucin and tyrosin. The water content was much more 
considerable than that of adult fasces ; next to water, the chief 
constituents, reckoned according to their weight, were the 
masses of bacteria, mucus, and epithelium, next the fat and 
fatty acids, and finally the salts. Of fifteen parts of solids 
in one hundred parts of faeces, one and a half are inorganic, 
thirteen and a half organic; of the latter, fat and fatty acids 
constitute from two to three parts, there are traces of proteids 
up to 0.2 part and cholesterin up to 0.2 part; of the remnant, 
from eight to eight and a half parts consist of bacteria, mucus, 
and epithelial cells. The fagces never show a uniform propor- 
tion in their different ingredients. 

Blauberg 13 found cholesterin always present, also lecithin, 
but only in minute amounts. Paul Miiller 194 also found a 
small amount of lecithin uniformly present. Bile acids are 
present in small quantities; Jacubowitsch denies that glyco- 
cholic acid is present, but Baginsky states that he has found it. 

Blauberg' s tests for nucleins in the faeces of breast-fed infants 
resulted negatively, but he was able to demonstrate them in 
the faeces of artificially fed children. While Knopfelmacher 
could detect no albumin remnant in the faeces of breast-fed 
infants, Blauberg finds that, as a rule, albumin is present in 
minute amounts during the first week of life. These may be- 
come considerable if there are digestive disturbances. 

Biliary residues are abundant; the following ferments have 
been discovered: a saccharifying ferment (Wegscheider, 
Moro), an inverting ferment (Jacks, Miura), and a pepto- 
nizing ferment (Baginsky). 

There are normally present a small amount of mucus and 
hosts of bacteria.' 

Marfan. 105 The faeces of an infant fed on cow's milk (even 
if it is sterilized, and especially if the milk is given undiluted) 



DIGESTION. 91 

are noticeably different from the evacuations of the nursing- 
infant. They are firm, pasty, somewhat dry, and of a pale 
yellow color with a feebly ammoniacal odor. After evacuation 
their color at times turns gray (Uifelmann), whereas the stools 
of breast-fed infants are apt to assume a greenish hue. The 
reaction of the stools is generally alkaline or neutral ; at times 
it is feebly acid. The alkalinity results either from ammoniacal 
fermentation or from the excess of mucus which is apt to be 
present owing to a slight degree of catarrh. Blauberg found 
lactic acid, fatty acids, and iron in decidedly larger quantities 
in the faeces of the breast-fed than of the bottle-fed infant. 
Indol is more frequently present in the evacuations of artifi- 
cially fed infants (Uffelmann). 

To conclude, the faeces of an infant fed on cow's milk con- 
tain more proteids (nucleins), fat, lime salts, and phosphoric 
acid, and less iron, and they are more copious relatively to the 
amount of food ingested than is the case in breast-fed infants.* 

Biedert. 7 Under the microscope casein appears as finely 
granular masses; the fat-droplets resemble mother-of-pearl, 
and are scattered through the faeces in moderate quantity. 
These run together into larger drops in the evacuations of 
young breast-fed infants and when there are digestive dis- 
turbances. We also find fatty acid crystals and salts of the 
fatty acids which are either star-shaped or arranged in clus- 
ters, or form glistening yellowish amorphous clumps. Mucus 
appears as hyaline delicately folded bands, which run through 
the field, often with round cells or blood-cells sticking to them. 
Many bacteria are present. 

Biedert gives the following directions for the examination 
of faeces. If proteids are present in the form of whitish lumps, 

* Knopfelmacher 8T in 1899 investigated the so-called casein flakes in 
the faeces of dyspeptic infants fed on cow's milk, and found that they 
contained from 2.988 to 3.53 per cent, nitrogenous material, twenty- 
five to forty per cent, fat, and 18.08 per cent, ash (the faeces were dried 
on the water-bath, hence not free from water ) . 



92 THE ARTIFICIAL FEEDING OF INFANTS. 

the specimen should be diluted with distilled water in a test- 
tube, after which Millon's reagent should be added. If the 
masses consist chiefly of proteids, they will form reddish lumps ; 
if they are mingled with any considerable quantity of soaps 
or salts, the latter will become soluble and the solid masses 
or lumps will disintegrate. If the fluid is heated, an excess 
of fat can be recognized by the presence of fat-globules. Under 
the microscope these white lumps are recognized by their finely 
granular consistence; they are structurally similar to milk- 
clots, and enclose fat-droplets within the finely granular casein. 
Fine waxy threads of mucin enclosing mucus cells in their 
meshes are to be seen, and must be differentiated from the 
above. 

Absorption. 

Marfan. 105 The amount of food absorbed and assimilated 
by the infant fed on cow's milk is estimated at ninety-three 
per cent, instead of ninety-six per cent, for the breast-fed 
infant. The percentage of casein absorbed by the breast-fed 
infant is given by Michel as from ninety-four to ninety-nine 
per cent. According to the researches of Eaudnitz, Lange, 
Bendix, Grosz, Lange and Berend, Knopfelmacher, Keller, and 
Michel, the proportion of nitrogenous matter absorbed by the 
intestine in infants fed on cow's milk is very variable, but 
generally less than that found in nursing babies; it varies 
between ninety-three and seventy per cent. If the child suffers 
from digestive disturbances, the amount will be still lower. 
Where there is no digestive disturbance, the utilization of lac- 
tose will be about the same in the breast-fed and the artificially 
fed infant; but the absorption of mineral salts, especially of 
lime and phosphoric acid, is decidedly less complete in the 
bottle-fed infant. Biedert emphasizes the importance of the 
form of emulsion in which the fat exists: the finer it is the 
better will it be absorbed. The proportion of fat absorbed 
varies from ninety to ninety-eight per cent. ; it is always higher 
in the breast-fed infant. 



DIGESTION. 93 

The Stools in Pathological Conditions. 
Abnormal types of stools may be classified, according to 
Chapin, 201 as follows : 

I. Green Stools. — Stools can only be considered green when 
that condition is evident immediately upon their passage. 
The color is due to fermentation, which doubtless results from 
bacterial action. All stools become green a certain time after 
passage, causes by oxidation of the air. 

II. Curdy Stools. — Curdy lumps may be produced by un- 
digested casein or fat. The former are hard and yellowish, 
while the latter are soft and smooth like butter. 

III. Slimy Stools. — These are the result of catarrhal in- 
flammation. When the mucus is mixed with fecal matter, the 
irritation is high up in the bowel; but when flakes or masses 
of mucus are passed, the trouble is near the outlet. 

IV. Yellow, Watery Stools. — These are seen in depressed 
nervous conditions, especially in the hot days of summer, when 
the bowel is relaxed and the inhibitory fibres of the splanchnic 
nerves do not act to advantage. 

Y. Very Foul Stools. — These are caused by decomposition 
of the albuminoid principles of the food. 

VI. Profuse, Colorless, Watery Stools, with Little Fecal 
Matter. — These are doubtless caused by an infective germ akin 
to that of Asiatic cholera. This condition is known as cholera 
infantum. 

These types are rarely seen alone, but are frequently found 
in all sorts of combinations (except the last). 



CHAPTEE V. 
MODERN METHODS OF INFANT FEEDING. 

The views of the leading pediatrists of Germany, France, 
England, and the United States differ more or less widely on 
the subject of infant feeding, yet certain general principles 
may be evolved from their teachings. Short abstracts of the 
views of Biedert, Monti, Baginsky, Holt, Eotch, and other 
prominent teachers abroad and in this country have been pre- 
pared that the reader may learn how great a variety of methods 
have been advocated for the artificial feeding of infants. 

Biedert 7 advises that cow's milk should be diluted three 
or four times when it is to be given to a very young infant 
or one with a weak digestion ; after the first two to three weeks 
dilute with twice the quantity of water; from two to three 
months increase gradually to equal parts; from four to six 
months give two parts of milk to one part of water, then three 
parts of milk to one of water, four to one, and from the eighth 
to the twelfth month pure milk. The change in strength of 
the addition should be made when the child ceases to gain in 
weight, provided the digestion is perfect. He advises the use 
of pure grape-sugar or lactose, to make a proportion of six 
per cent, in the diluted milk. Cane-sugar or beet-sugar may 
be used instead; the latter is cheaper. Lactose, on the whole, 
seems preferable; it is the natural sugar present in milk, and 
also has the property of aiding in the digestion of proteids. 
By splitting up into lactic acid it acts as an intestinal anti- 
septic. 

Wheat-, barley-, or oatmeal-water, or plain water, may be 
used as diluents, according to the state of the child's diges- 
tion. 

94 



MODERN METHODS OF INFANT FEEDING. 95 

Biedert estimates that from one hundred and fifty to two 
hundred cubic centimetres of food are necessary for each kilo- 
gramme of body weight during the twenty-four hours. Feed 
at first every two hours; then rapidly diminish the number 
of feedings to eight, seven, six, or even five in the twenty-four 
hours; avoid night feedings if possible. When a child is 
weakly, it can be fed every two and a half or three hours 
from four a.m. to ten p.m., — that is, seven or eight meals a 
day. 

Biederfs Cream Mixture. 











Casein. 


Fat. 


Sugar. 


Calories 


Age. Cream. 


Water. 


Sugar. 


Milk. 


Per 


Per 


Per 


in 100 


Litre. 


Litre. 


Grammes 


Litre. 


cent. 


cent. 


cent. 


ce. 


First month £ 


3 
8 


18 




0.9 


2.5 





47 


Second month £ 


t 

3 
8 


18 


JL 


1.2 


2.6 


5 


49 


Third to fourth month . . % 


18 


I 


1.4 


2.7 


5 


51 


Fourth to fifth month . . | 


3 
8 


18 


4 


1.7 


2.9 


5 


54 


Sixth to seventh month . £ 


t 


18 


3 

8 


2.0 


3.0 


5 


56 


Eighth to twelfth month. £ 


1 
4 


12 


3 
4 


2.5 


2.7 


5 


56 



A cream containing from eight to ten per cent, fat should 
be used in this mixture. In his latest edition Biedert recom- 
mends six per cent, sugar instead of five per cent. Indi- 
cations for using the cream mixture are given by Biedert as 
follows: prolonged digestive disturbances which do not yield 
to simple dilution of cow's milk, constipation alone or alter- 
nating with enteritis, and mucous enteritis. A bad result 
means, of course, that the digestive apparatus cannot handle 
fat. If fat diarrhoea occurs, we may have to used skimmed 
milk. 

Biederfs Cream Conserve is a paste containing 7.1 per cent, 
casein, 15.5 per cent, fat, and thirty-five per cent, sugar, ster- 
ilized by heat. A large number of formulas can be constructed 
by the addition of milk and water to this conserve. For ex- 
ample : 



96 THE ARTIFICIAL FEEDING OF INFANTS. 

Mixture No. 1. 
One tablespoonful conserve. . . . ") f 1.0 per cent, albumin 
Thirteen tablespoonfuls water. . r — s 1.7 per cent. fat. 
Two tablespoonfuls milk J v 8.3 per cent, sugar. 

Mixture No. 5. 
One tablespoonful conserve. . . . "} f 1.5 per cent, albumin. 
Thirteen tablespoonfuls water. . > = ■< 2.1 per cent. fat. 
Six tablespoonfuls milk J ^8.5 per cent, sugar. 

Many of the other thickened cream conserves, such as Lah- 
mann's Vegetable Milk, Loeflund's Cream Conserve, and Allen- 
bury's Infant Foods, are componnded on similar lines. 

At the 1899 meeting of the Society of German Naturalists 
and Physicians Biedert stated that we should not use one 
type of milk for all cases, but a mixture of milk, cream, water, 
or other diluents which can be altered at will. 

Heubner 70 thinks that healthy children can be given large 
amounts of proteids without harm; an excess of proteids is 
less harmful than an excess of fluids. Basch has shown that 
casein is well digested by trypsin in the space of from four 
to five hours without leaving any nuclein remnant. The 
presence of undigested casein in the diarrhceal stools does not 
prove that the healthy infant cannot digest casein in proper 
amount. 

Heubner's method, which can also be called the calorimetric, 
is based on the principle of diluting cow's milk as little as 
possible; it is intended to furnish a food mixture which will 
closely resemble mother's milk in the number of calories it 
contains. 

Heubner's Mixture is prepared as follows : one pint of cow's 
milk is diluted with half a pint of oatmeal- or barley-water, 
sterilized in the Soxhlet apparatus for fifteen minutes, and 
quickly cooled and kept cool till ready for use. Instead of 
the oatmeal-water, two teaspoonfuls of Kademann's or Kufeke's 
Meal may be added to a pint of water and boiled down to 



MODERN METHODS OF INFANT FEEDING. 97 

half a pint (from a half to three-quarters of an hour) . Enough 
lactose should be added to the mixture to make the percentage 
of sugar equal seven; this should be done in the last five 
minutes. 

One litre of this mixture will represent two per cent, pro- 
teids, 2.2 per cent, fat, and 7.2 per cent, sugar, and will be 
equivalent to five hundred and eighty calories. This mixture 
is not suited to every case; for children of very low weight, 
with weak digestive powers, and for sick infants we must use 
sometimes a weaker mixture, — namely, we must dilute the 
milk one-half or two-thirds. The child should be fed every 
three hours. 

Feer 53 gives in the subjoined table the amounts of cow's 
milk, water, and lactose administered in the Heubner-Hoff- 
mann-Soxhlet Mixture at different periods of the infant's life, 
and compares the figures with the quantities required by the 
child at the breast. They represent the total quantity in the 
twenty-four hours. 

Breast-milk. CWs milk. Water. Lactose. 
Cc. 

First week 300 

Second week 550 

Third week 600 

Fourth week 6-50 

Fifth week 700 

Sixth week ... 750 

Seventh to eighth week 800 

Ninth to twelfth week 825 

Thirteenth to sixteenth week 875 

Seventeenth to twentieth week 925 

Twenty-first to twenty-fourth week. . 975 

Heubner. 70 In the nourishment of the breast-fed infant the 
quantitative are greater than the qualitative differences; this 
without prejudice to the growth of the child. The number 



Cc. 


Cc. 


Grammes. 


50-200 


100 


12 


350 


200 


24 


400 


200 


24 


400 


250 


30 


450 


250 


30 


500 


250 


30 


520 


300 


37 


550 


300 


37 


600 


300 


37 


600 


350 


43 


650 


350 


43 



98 THE ARTIFICIAL FEEDING OF INFANTS. 

of calories required by children of equal weight and develop- 
ment varies greatly. This has been shown by a series of obser- 
vations on the children of physicians. Children of equal weight 
and age would take quantities varying widely, some requiring 
twice as much as others. Qualitative tests of the milk were 
not carried out, but it is not likely that they varied sufficiently 
to account for such differences. The mothers all lived under 
good hygienic conditions. 

Heubner gives the following table of the number of calories 
consumed by children on different milk mixtures : 

■» T ., , Heubner' s Biedert's 

Mother s Two-thirds One-third 

muK - Mixture. Mixture. 

Calories. Calories. Calories. 

A child weighing 3300 grammes will take : 328 360 214 

A child weighing 4000 grammes will take : 409 450 260 

A child weighing 4500 grammes will take : 502 540 318 

A child weighing 5400 grammes will take : 496 540 350 

Camerer and Soldner find very low fat percentages in 
mother's milk in the latter months of lactation. Between the 
third week and the fourth month the average is 3.66 per cent. 
We can assume an average of 3.5 per cent, without danger of 
giving too high a figure. In one litre of mother's milk there 
are from ten to twelve grammes of proteids, yielding from 
forty-one to forty-nine calories; thirty-five grammes of fat, 
yielding 325.5 calories; and sixty-five grammes of sugar, yield- 
ing 266.5 calories; total, six hundred and twenty calories. 

Children of equal age and weight, fed on greatly different 
amounts of milk (even double the quantity, vide supra), will 
show a like increase in weight. It is evident, then, that differ- 
ent children require a different number of calories per kilo- 
gramme of body weight for their growth and nourishment. 
If this difference exists in human milk, we should expect to 
find that the same holds good in the case of artificially fed 
infants. Some will thrive on low proteids and high fat per- 



MODERN METHODS OF INFANT FEEDING. 99 

centages; or, vice versa, on high proteids and low fat; or on 
a mixture rich in sugar, such as condensed milk preparations; 
or on preparations containing starches; or even on peptone 
and egg albumin, granting the necessary cleanliness in the 
preservation and the preparation. These kinds of foods are 
useful in tiding the infant over to a diet of cow's milk, slightly 
diluted, or to mixed feeding. They do not all possess the same 
food value. Some make more demands on the infant's diges- 
tion than do others; at the same time, infants seem to be 
able to dispose of very differently constituted food-stuffs. We 
should not depend on the infant's powers of digestion, but 
should as far as possible take the child's natural food (breast- 
milk) as an example. 

Gaertner's Milk has an average value of six hundred and 
twelve calories per litre, and Backhaus Milk six hundred and 
thirty calories to one litre. 

Proteids. Fat. Sugar. 

Per cent. Per cent. Per cent. 

Woman's milk 1-1.2 3.5-4 6.5-7 

Backhaus Milk 1.75 3.25 6.75 

Gaertner's Milk 1.67 3.2 6.00 

Heubner's Mixture (two-thirds strength). 2.27 2.3 7.00 

Heubner is inclined to think that scurvy may follow the pro- 
longed use of these prepared infant foods. While sterilization 
may also carry dangers with it in this respect, it is unfortu- 
nately necessary. 

The value of the artificial cream foods is at present estab- 
lished more on a theoretical than a practical basis. The value 
of any child's food depends largely on the cleanliness observed 
in its handling and preparation, its administration in correct 
quantities (without other food), and the general hygiene sur- 
rounding the child's person. 

Bendix 10 thinks that it is not so much the question how 
to render the casein digestible as how to reduce it to the proper 

LofC. 



100 THE ARTIFICIAL FEEDING OF INFANTS. 

proportion by dilution with water or barley-water. He agrees 
with Heubner that one should give the actual amounts of the 
food constituents which are necessary without laying too much 
stress on the relative dilution. 

Seifert, 59 in the last edition of G-erhardt's text-book, advises 
that the Heubner-Hoffmann Mixture should be used, sterilized 
in the Soxhlet apparatus. The latter is not perfect, but it is 
at present the best means we have for rendering the milk sterile 
and so adapted to the infant's use. 

Henoch, 71 in the last edition of his " Lectures on Children's 
Diseases/' recommends for the first two or three months one 
part of milk to two or three parts of water; from four to six 
months one part of milk to two of water; from six to nine 
months equal parts, or two parts of milk to one of water ; after 
ten months he gives whole milk. Each case should be fed 
according to its particular needs. 

Baginsky 6 finds that two essential difficulties exist in the 
problem of infant feeding : first, the qualitative and quantita- 
tive differences in the chemical composition of woman's milk 
and cow's milk; second, the presence of bacteria and their 
toxins. When the dirt and bacterial content of cow's milk are 
diminished, the results of feeding children with it are so satis- 
factory that in the case of healthy infants elaborate methods 
of altering its composition become of little value or even super- 
fluous. With regard to the first point, we must reduce the 
proteid percentage and add sugar. The numerous quantitative 
variations in the proteid content of mother's milk prevent the 
establishment of an absolute standard for the degree of dilu- 
tion ; neither can the total quantity of food to be administered 
daily be rigidly determined. As the amount of milk which 
a child at the breast will take varies within considerable limits 
in each individual case, so also in the case of cow's milk it 
is impossible, in the absence of a more definite basis for com- 
putation, to establish any absolutely fixed or definite standard 
for the total quantity to be given. Biedert has calculated that 



MODERN METHODS OF INFANT FEEDING. 101 

when cow's milk is diluted so that its casein content amounts 
to one per cent., the infant requires for each kilogramme of 
his body weight two hundred cubic centimetres of milk. This 
rule may hold good for many cases, but the degree of dilution 
and the total daily quantity of food must be determined finally 
by the digestive capacity in each individual case. The latter is 
best estimated by the use of the scales. Some children certainly 
tolerate more concentrated nourishment and more liberal quan- 
tities of food than others. In fact, many authors, especially 
the French (Budin, Yariot, and others), advise to give whole 
milk from the beginning. On the other hand, some infants 
digest casein with difficulty, while in other cases richness in 
fat content is the stumbling-block. Only the most careful 
observation of the child's general condition and inspection of 
the faeces will save the physician from mistakes in treatment. 
In general one can begin with a dilution of three parts of water 
and one part of milk, gradually diminishing the amount of 
water until, towards the end of the third month, a mixture 
of equal parts of milk and water is reached. Instead of water, 
dilute oatmeal-water may be used, or solutions of one of the 
infant foods. The addition of milk-sugar must not be for- 
gotten. Whole milk is often well tolerated at the end of the 
ninth month. In view of what has been said, the following 
table of quantities at each feeding is to be considered merely 
a general guide for the practitioner; it is not intended to 
take the place of careful personal observation and study of 
the needs of each individual case (size, weight, power of 
digestion, etc.). Baginsky has found this method of dilution 
satisfactory in a practice covering many years. He sees no 
reason to modify it in any essential respect, notwithstanding the 
fact that the recent metabolism work of Heubner and Eubner 
seems to controvert its principles. Each child has its individ- 
ual powers of digestion. It is well to begin with the more 
dilute mixtures and to advance to those more concentrated, 
guided always by the results of careful clinical observation. 



102 



THE ARTIFICIAL FEEDING OF INFANTS. 



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MODERN METHODS OF INFANT FEEDING. 103 

The use of barley-water and similar weak starchy prepara- 
tions has long been recommended and is of undoubted value 
in rendering milk more digestible by lessening the size of the 
clots. Kudisch's proposal to effect the same by the addition 
of dilute hydrochloric acid has not found favor. Montr's Whey 
Mixture, Voltmer's Mother's Milk, and Backhaus Milk are 
defective in that they show a departure from the normal, — 
a deficiency in either fat, albumin, or sugar which is hard to 
remedy. Doubtless they will all give good results in a large 
number of cases, but as certainly not in all cases, and faulty 
nutrition will result unless the greatest care is exercised. It 
is a mistake to use calories as a basis for feeding infants; 
reckonings of this kind are of value in estimating the total 
food requirements of the organism, but one should never, on 
this theoretical basis, attempt to substitute fat for proteids 
or sugar for fat. 

The infant's body requires, even more than the adult's, a 
definite quantity of food-stuffs for the period of growth, and 
it will more easily select and assimilate the same from a 
mixture of apparently faulty qualitative composition than 
it will handle a food which theoretically and quantitatively 
is correctly put together to represent a certain value in calo- 
ries. If the organism needs fat, it will not thrive if sugar 
is offered in its place; the same is true of albumin. Herein 
lies the great danger of the modern habit of considering this 
question from the chemical stand-point. 

Baginsky does not recommend the use of Bieth's Albumose 
Milk, Lahmann's Vegetable Milk, Graertner's Fat Milk, or 
Loeflund's Cream Conserve. All conserves are distinctly in- 
ferior to fresh cow's milk, and their use is apt to be followed 
by severe anaemia and scurvy. 

Monti." When cow's milk is to be used as an infant food, 
the following principles must be kept in mind : ( 1 ) The acid- 
ity must be diminished, as it is three times that of mother's 



104 THE ARTIFICIAL FEEDING OF INFANTS. 

milk.* (2) The casein must be diminished and its tendency 
to clot in large lumps altered; the lesser amount of soluble 
albuminoids in cow's milk must be made up and their relative 
proportion to the casein present improved. (3) The lesser 
amount of fat and the unfavorable proportion of fat to casein 
must be considered. (4) The bacteria must be rendered harm- 
less. (5) The lesser amount of sugar must be compensated 
for. (6) The salts must be reduced and maternal conditions 
imitated as closely as possible. Monti prefers mixed feeding 
to the exclusive use of artificial food, and, even if the mother's 
milk is defective, he advises to wait until after the sixth week 
before giving cow's milk, since the latter will be better toler- 
ated after that time. 

Monti then criticises the methods of Heubner, Hoffmann, 
and Soxhlet. The Heubner-Hoffmann Mixture is presented in 
a very concentrated form and will not be as well assimilated 
as mother's milk; it contains too little soluble albumin, espe- 
cially for the first months of life, and the percentage of fat 
is too low. Soxhlet has endeavored to supply the deficiency 
in fat by the addition of lactose. The amount of lactose 
needed is based on Buhner's statement that one hundred parts 
of fat are isodynamic with two hundred and forty-three parts 
of sugar; then 1.32 parts of fat will equal 3.19 parts of milk- 
sugar. Cow's milk is mixed with one-half its amount of 12.3 
per cent, lactose solution ; this gives the following percentages : 
water 85.3, proteids 2.37, fat 2.46, fat represented by lactose 
1.32 (3.78 fat), lactose as equivalent for absent fat 3.19, natu- 
ral lactose content 3.25, lactose added to supply deficiency 
2.96; total lactose content 9.40. In Monti's opinion, Soxhlet's 
Mixture contains too much lactose. This is apt to cause diar- 
rhoea, and is therefore not a good substitute for fat. 

* Wolf and Friedjung, in Monti's clinic, found that the acidity of freshly 
milked breast-milk was only 0.1, tested with a decinormal soda solution ; 
whereas the acidity of raw cow's milk, even when fresh, amounted to 1.1 
and over. (Eeported at Paris Congress. ) 



MODERN METHODS OF INFANT FEEDING. 105 

Marfan s Mixture contains too much lactose, excessive pro- 
teids, and is too concentrated, like the Heubner-Hoffmann 
Mixture. Monti therefore condemns it. The same criticism 
applies to Sieberfs method. 

Monti considers that Biedert, in his Cream Mixtures, gives 
quantities which are in excess of the actual capacity of the 
stomach, that he increases the proportion of proteids too rap- 
idly, and that he gives a slight excess of proteids and fat during 
the first weeks of life. Since fresh cream varies in its compo- 
sition, and since its digestibility is altered by sterilization, its 
use should be restricted to those cases in which no other form 
of milk mixture will be tolerated. 

Biedert* s Cream Conserve, if well prepared and completely 
sterile, may be useful for a certain class of cases, but is not 
adapted to take the place of fresh milk ; Heubner expresses the 
same opinion. 

Vigier's Humanized Milk (1893) is prepared by taking a 
definite quantity of milk and dividing it into two equal parts. 
The first half is left untouched; the second half stands until 
the cream separates completely, when the cream is removed. 
The skimmed milk is coagulated and the serum obtained is 
added to the first half, as is the separated cream. This is 
sterilized. Its composition is as follows, according to Gau- 
trelet: casein 2.36 per cent., fat 3.75 per cent., lactose 4.10 
per cent., carbohydrates 0.81 per cent., salts 0.7 per cent. 

Monti's Whey-Milk Mixture is prepared in the following 
manner. The whey is separated from one litre of good cow's 
milk, rich in fat, by heating the same to 35° C. and adding 
one gramme of French lab-ferment dissolved in forty cubic 
centimetres of distilled water. The latter must be prepared 
freshly each time. Allow the mixture to stand until it be- 
comes jelly-like, which will require from twenty-five to thirty 
minutes; then apply heat again up to 68° C; this will de- 
stroy the lab-ferment. Let the mixture stand till cool and 
filter through a silk cloth. Whey prepared in this manner 



106 THE ARTIFICIAL FEEDING OF INFANTS. 

will be alkaline, of a specific gravity of from 1020 to 1027, 
and will contain : casein 0.03 per cent., soluble albumin from 
0.80 to one per cent., fat one per cent., sugar from 4.5 to five 
per cent., salts 0.7 per cent. 

For the first five months of life a mixture of equal parts 
of milk and whey is suitable; to older infants, if not im- 
proving as they should, two parts of milk to one of whey should 
be given. After cooling, the mixture is put in sterile bottles 
and pasteurized in the Soxhlet apparatus for from ten to 
fifteen minutes at from 68° to 70° C. ; it is then cooled to 
8° C. and kept at this temperature until used. 

The composition of the mixtures will be as follows : 



Casein. Soluble albumin. Fat. Sugar. Salts. 

Per cent. Per cent. Per cent. Per cent. Per cent. 

Mixture No. 1 1.22 0.8-1.0 2.33 4.5-5 0.7 

Mixture No. II 1.61 0.8-1.0 3.11 4.5-5 0.7 



Monti considers that these mixtures correspond very closely 
to mother's milk in their proteid percentages, while the con- 
tent of fat and sugar is lower than in mother's milk. He 
believes that young infants thrive better on low fat and sugar 
percentages in artificial feeding than when these ingredients 
are present in larger quantity. Wolff and Paccini have ob- 
tained good results with the Monti Mixture; the latter used 
two parts of whey to one of milk rich in fat, and so obtained 
a mixture containing casein one per cent., fat three per cent., 
sugar five per cent., and rather more soluble albumin than in 
the Monti Mixture. 

Schlossmann has emphasized the value of a mixture of 
whey and cow's milk from the theoretical stand-point. He 
thinks that the addition of soluble albumin to cow's milk has 
a decided influence on the form of casein precipitation. To 
demonstrate this, he took a cream containing seven and a half 
per cent, fat and 1.06 per cent, casein, and diluted one-half 



MODERN METHODS OF INFANT FEEDING. 107 

the quantity with equal parts of water and the other half 
with an equal part of one per cent, serum-albumin solution. 
The latter mixture resembles mother's milk in its chemical 
composition, containing 3.75 per cent, fat and 0.8 per cent, 
casein with 0.5 per cent, albumin. The first half of the mix- 
ture contains just as much fat and casein, but practically no 
albumin. These mixtures were both tested with artificial gas- 
tric juice in an incubator. The first half showed the for- 
mation of large, firm, uneven clots; the second half showed 
precipitated casein in a finely divided condition, covering the 
bottom of the tube as a finely granular deposit of soft and even 
consistency. 

Use of Diluents. — In Monti's opinion, there is no advantage 
to be gained from the use of barley-water, oatmeal-water, etc., 
that cannot be equally well obtained with plain water. The 
casein clots are just as coarse in either case, and digestion is 
not rendered any easier. Moreover, the cereals are apt to cause 
meteorism and dyspeptic symptoms, especially in young infants, 
and have no especial nutritive value. 

At the Paris Congress of 1900 Monti recommended the use 
of sodium carbonate to counteract the acidity of artificial milk 
mixtures. The special advantage gained by the use of whey- 
milk mixtures is that we thereby increase the proportion of solu- 
ble albumin and render coagulation by lab-ferment more nearly 
like that which occurs in the stomach of the breast-fed infant. 
The fat content of cow's milk is reduced by this degree of 
dilution, and to make up the deficiency by the addition of 
cream cannot be recommended, since the milk will then con- 
tain relatively too many fatty acids. The infant does not 
digest and assimilate cream readily: moreover, the fat emul- 
sion is affected by centrifugation, so that large drops rise to 
the surface. Two per cent, is a quite high enough fat content, 
and will suffice for the infant's needs if the correct proportion 
of proteids and sugar is given. The sugar content is best regu- 
lated by the addition of pure whey. 



108 THE ARTIFICIAL FEEDING OF INFANTS. 

Monti disapproves of sterilization on account of the great 
changes it causes in milk; he prefers to heat for ten minutes 
at from 60° to 70° C, and then to cool to 6° C. until used. 
He advises to allow three-hour intervals between feedings, to 
suit the amount to the capacity of the stomach, and to give 
proportionately less than the child at the breast would take, 
since cow's milk is digested with more difficulty. 

Lahmann's Vegetable Milk, according to Stutzer's analyses, 
contains : fat twenty-five per cent., nitrogenous substances, prin- 
cipally plant-albumin, ten per cent., sugar and other non- 
nitrogenous substances 38.5 per cent., mineral materials 1.5 
per cent., water twenty-five per cent. It is asserted that the 
presence of vegetable albumin in this preparation renders the 
digestion of the proteids more easy by furnishing conditions 
approximating precipitation of the casein of mother's milk 
by lab and peptic ferments. Since this preparation contains 
elements which are not found in mother's milk, it cannot be 
considered a normal food. 

Bachliaus Milk is prepared as follows, according to the latest 
modifications of its originator. 16 Good fresh milk is separated 
by centrifugation into cream and skimmed milk; a mixture 
of trypsin, lab-ferment, and a one-half per cent, solution of 
sodium carbonate is then heated to a temperature of 40° C. 
and added to the skimmed milk. The casein is first coagulated 
by the lab, then the trypsin in the presence of the alkali re- 
dissolves and peptonizes part of the casein, so that at the end 
of half an hour 1.25 per cent, of soluble proteids is present. 
By heating to 80° C. the action of the enzyme is destroyed. 
The separated casein is then removed by straining or by cen- 
trifugation, and cream is added of sufficient concentration to 
give 3.5 per cent, of fat and 0.5 per cent, of casein; finally 
one per cent, of lactose is added, and the mixture is put in 
separate bottles and sterilized. 

This preparation is practically a peptonized milk, and time 
and care are requisite for its manufacture. Biedert and Heub- 



MODERN METHODS OF INFANT FEEDING. 109 

ner agree that the natural properties of milk are altered by the 
artificial modifications which this process requires. 

Voltmer's Mother's Milk. — This is essentially a peptonized 
milk which has received additions of fat and sugar. It may 
be made fresh or as a conserve; three mixtures of different 
strengths are prepared. The composition of the conserve is 
liable to vary. Heubner considers Voltmer's Milk valuable 
as a temporary expedient in weakly infants, especially for 
the first weeks of life. Drews 45 thinks that it is adapted 
to general use, both for sick and healthy children, and that 
children fed on it are no more liable to gastro-intestinal dis- 
turbances than those at the breast. He cites a large number 
of cases. 

Loeflund's Peptonized Child's Milk. — This food is similar 
to the last-named preparation, and can be used temporarily 
in like manner. In Monti's opinion, it has no advantages over 
milk which is peptonized at home. 

Loeflund's Cream Conserve differs from Biedert's in con- 
taining maltose instead of cane-sugar. Its analysis reads: 
sugar fifty per cent., fat twenty-three per cent., proteids five 
per cent., ash 1.8 per cent., water 20.2 per cent. In Biedert's 
estimation, the presence of maltose is useful. 

Gaertner's Milk 7 is made by dividing into two equal parts in 
the separator a bulk of milk diluted equally with water. The 
mixture will then contain nearly all the fat in an emulsified 
state, and one-half the quantity of proteids, sugar, and salts con- 
tained in the original milk. Apart from this, Biedert sees no 
particular advantage in Gaertner's Milk over ordinary cream 
mixtures. Its specific gravity ranges from 1020 to 1030, and 
an analysis of its contents gives the following average : casein 
1.76 per cent., fat three per cent., sugar 2.4 per cent. It is 
not as sweet as whole milk, but the taste is not unpleasant; 
it clots in smaller flakes than cow's milk. 

Marfan has observed that large fat-droplets collect on the 
surface of Gaertner's Milk, after it has stood for some time, 



110 THE ARTIFICIAL FEEDING OF INFANTS. 

and form a yellow skim. After several hours the emulsion 
is not readily re-formed. 

Monti thinks that the composition of Gaertner's Milk is 
inconstant; the reports as to its use are very contradictory. 
Monti asserts that the centrifugation disturbs the emulsion 
of the fat and causes a conglomeration of the fat-globules. 
The influence of the fat-corpuscles in favoring the finer coagu- 
lation of the casein is thus impaired and absorption is hindered. 
Microscopical examination confirms these statements. In 
Monti's experience, the amount of fasces is apt to be large when 
infants are fed on Gaertner's Milk. Gaertner's Milk may be 
used temporarily to meet definite indications, but it must not 
be considered an absolute substitute for mother's milk. 

Thiemich and Papiewsky, 144 from the observation of thirty 
cases, conclude that Gaertner's Milk can be used when there 
are digestive disturbances, but possesses no advantages over 
dilutions of cow's milk. Czerny thinks that Gaertner's Milk 
and Backhaus Milk are not efficient substitutes for mother's 
milk when the child is sick. Fat milk is useful in constipation, 
but in many cases it is not well borne. Escherich is a strong 
advocate of the use of Gaertner's Milk; many of the good 
results which he obtained were in the case of healthy infants 
who had just been weaned or who were getting mixed feeding. 

John" Lovett Morse, of Boston, in " A Consideration of Pro- 
fessor Gaertner's Mother's Milk," 218 states that its manufacture 
was first begun in this country in 1897. His conclusions in 
regard to it are as follows. It contains only the constituents 
of cow's milk, and they are present in approximately the same 
proportions as in human milk; but they are not constant, are 
unknown to the consumer, and are insusceptible of modifica- 
tion. It is not a " fresh" food, and costs as much or more 
than modified milk which is freshly prepared and whose pro- 
portions can be varied. 

Rieth's Album ose Milk is a preparation of soluble albumin, 
obtained by heating egg albumin to over 130° C. Cream and 



MODERN METHODS OF INFANT FEEDING. HI 

lactose are added in sufficient quantity to make a product simi- 
lar to mother's milk. Monti thinks that it is not fit to be a 
permanent food, but agrees with Hauser and Baginsky that 
it may give good results in isolated cases. 

An objection which applies to all of these products is their 
cost. Baginsky deserves credit for having drawn attention to 
the fact that these foods do not give us the same results as fresh 
milk; marked anaemia and scorbutic affections frequently fol- 
low their prolonged use, notwithstanding that the children 
become fat. At the time when Liebig's soup and condensed 
and conserved milk preparations were in general use, Monti 
often noticed that children fed on fresh cow's milk were not 
subject to anaemic and hemorrhagic disorders. (In general it 
may be said of all these preparations that none of them justi- 
fies the claims put forward by their originators; their use 
must necessarily be limited, and they cannot take the place 
of properly modified cow's milk. — Editors.) 

Steffens Veal Broth. — Steffen has lately recommended a 
mixture of cow's milk, veal broth, and cream, prepared as 
follows. One hundred and forty grammes of veal are added 
to half a litre of water and cooked for from a half to three- 
quarters of an hour, boiling water being added from time to 
time to keep up the original quantity. Salt must not be added. 
Veal broth and milk are mixed in equal parts, and to each 
one hundred cubic centimetres of the mixture five cubic centi- 
metres of cream and 3.8 grammes of lactose are added; it is 
then sterilized in the Soxhlet apparatus. This mixture con- 
tains : casein 1.8 per cent., fat 3.1 per cent., sugar 6.2 per 
cent., salts 0.45 per cent. 

For the new-born one part of milk and three parts of broth 
are to be used; this will contain from 0.25 to 0.35 per cent, 
of salts, which is greater than the proportion in mother's milk. 
For the later periods of nursing two parts of milk and one 
part of broth should be given; if there is constipation, give 
less milk and more cream. 



112 THE ARTIFICIAL FEEDING OF INFANTS. 

This preparation has a pleasant taste and smell and an 
amphoteric reaction. The potassium salts in veal broth in- 
crease the alkalinity and facilitate the digestion of the casein. 
Good results were obtained by Steffen in his own experience 
of ten years; his father used the veal broth for twenty years 
with uniform success. Eickets was not observed. Both sick 
and healthy children took the mixture well. 

Gregor. 65 Malt Soup. — Fresh milk is obtained directly 
from the farm and cooled as usual. It must not be boiled. 
To two-thirds of a litre of water heated to from 50° to 60° C. 
one hundred cubic centimetres of Loeflund^s malt extract and 
ten cubic centimetres of an eleven per cent, solution of potas- 
sium carbonate are added. At the same time fifty cubic centi- 
metres of wheat flour are added to one-third of a litre of milk 
and stirred till an even consistence is reached. This is passed 
through a fine sieve, and then the two are mixed together and 
brought to a boil, with constant stirring. 

If one litre is to be given for the daily portion, heating to the 
boiling point requires from six to ten minutes. If from eight 
to ten litres are to be prepared, twenty to thirty minutes are 
required. To avoid overheating, remove the heat when a tem- 
perature of 94° C. is reached for the smaller and 98° C. for 
the larger quantity. The mixture as prepared is thin and 
has a good spicy taste of malt. In hot weather it should be 
kept cool and in sterile bottles. Sterilization is apt to cause 
separation of the fat, which impairs the nutritive value of the 
soup. For infants from one and a half to three months of 
age Gregor uses less malt extract and less flour ; and for infants 
from nine to fifteen months of age, half milk and half maltose 
solution (less malt is used to make the solution). Good results 
were obtained with this preparation in over seventy-five per 
cent, of the cases which presented themselves for treatment 
(including atrophic cases and severe gastro-intestinal diseases), 
seventy-three in all. Gregor recommends the use of malt soup 
in diluted form to infants under three months, provided that 



MODERN METHODS OF INFANT FEEDING. 113 

its administration can be closely supervised. It gives good 
results in gastro-intestinal affections, malnutrition, and rickets, 
and may be employed when the child is weaned or for mixed 
feeding. Keller also uses malt soup with good results. 

At the seventy-third meeting of the Society of German Natu- 
ralists and Physicians Salge presented a paper on the use of 
buttermilk for infant feeding. 142 He considers it adapted for 
the child's diet when convalescent from acute digestive disturb- 
ances and in atrophic cases. It may be added to malt soup or 
as a supplement to breast-milk. It must be fresh and clean and 
carefully prepared from sour cream. The average formula will 
be: from 2.5 to 2.7 per cent, proteids, 0.5 to one per cent, fat, 
and 2.8 to three per cent, sugar. According to Eubner, one 
litre will furnish seven hundred and fourteen calories. 

One hundred and nineteen cases were fed on it at the Charite 
(Berlin) ; of these, eighty-five gave favorable results. The 
faeces contained many lactic acid bacilli and were of firm con- 
sistence; in some cases there was constipation. To each litre 
of buttermilk fifteen grammes of meal and sixty grammes 
of cane-sugar were added, and it was then heated slowly to 
boiling. Investigations as to the absorption of proteids and 
fat, which are not as yet completed, show that the greater 
portion of them is absorbed. 

Schlossmann reported at the same meeting that he had fed 
one hundred and fifty infants on buttermilk with good results. 
If the gain in weight was not satisfactory, he added cream. 

Filatow, 58 of St. Petersburg, advises to give the new-born 
infant milk diluted three times with a solution of oatmeal-, 
rice-, or barley-water, adding two or three teaspoonfuls of 
sugar to each half-pint. From one to three months give one 
part of milk to two of water, from three to four months equal 
parts, from four to six months two parts of milk to one part 
of water, and after six months pure milk. This scheme can, 
of course, be varied to suit the infant's development and its 
powers of digestion. A child below five months of age can take 



114 THE ARTIFICIAL FEEDING OF INFANTS. 

at one time as many ounces as its age plus one, — e.g., at three 
months four ounces, at five months six ounces, etc. From 
six to twelve months give six ounces at a feeding. Up to the 
second month feed every two hours in the day and twice at 
night; from two to four months feed every three hours in 
the day and once at night, — seven meals in all. After this 
feed six times in the twenty-four hours. No starchy food 
should be given before the fourth month. Cleanliness in ob- 
taining and handling the milk is essential. In case the child 
cannot take cow's milk, try Biedert's Cream Mixture or Gaert- 
ner's Milk. 

Schlesinger, 139 ' 227 of Breslau, recommends the use of pure 
undiluted cow's milk for infant feeding; this may be sterilized 
if necessary. The calorie value of woman's milk is almost iden- 
tical with that of undiluted cow's milk. The more cow's milk 
is diluted the lower will its food value fall and the more in- 
sufficient will it become for the infant's needs. Dilution with 
water does not render the casein more digestible; the fact is, 
by diluting milk from two to three times we simply flood the 
system with water, for the child has to take a much larger 
quantity of food to get the necessary quotient for its proper 
growth. Such a flooding of the system entails greater work on 
the part of the organs of digestion and assimilation, and often 
leads to marked dyspeptic disturbances, gastric dilatation, and 
finally atrophy. Schlesinger therefore advises to give small 
quantities of whole milk even during the first month of life. 

Czerny 34 also believes that we injure the child by giving 
too weak dilutions, and that some of the normal salts in the 
economy will be washed out by an excessive administration 
of water. The danger of giving too much proteids is still 
greater, however; Czerny therefore agrees with Heubner that 
we should give concentrated mixtures containing a moderate 
amount of proteids. The intervals between feedings should be 
long, — at least four hours. 

Keller 84 considers that in the normal artificially fed in- 



MODERN METHODS OF INFANT FEEDING. 115 

fant the stomach contents are evacuated about three hours 
after taking food; free hydrochloric acid is present only two 
hours later. It has been observed that constant burdening of 
the stomach with food diminishes the secretion of hydrochloric 
acid and the gastric motility. In sick children we often find 
food remnants in the absence of hydrochloric acid as long as 
four or five hours after a meal. An interval long enough to 
allow the stomach to empty itself completely seems to be 
necessary for the re-establishment of the secretory and motor 
functions of the stomach. • 

The addition of maltose to milk diminishes the destruc- 
tion of the albuminoid substances in the economy, and per- 
mits the maintenance of nitrogenous equilibrium without the 
necessity for excessive proteids in the diet. It is therefore 
the best form in which to administer carbohydrates to in- 
fants. 

Schmid-Monnard, 127 of Halle, does not believe in the use 
of food which has been subjected to prolonged heat; fresh milk 
must be employed for the purposes of infant feeding, to which 
cream, water, and sugar are to be added. There are marked 
variations in the quantity of food required by artificially fed 
as well as breast-fed babies; the daily number of calories re- 
quired remains, however, about the same, — namely, one hundred 
and thirty-three calories per kilogramme of body weight for 
artificially fed and ninety-nine calories per kilogramme for 
breast-fed infants. The number of calories needed during 
the first six months varies from one hundred and seventeen to 
one hundred and thirty-nine per day for each kilogramme of 
body weight in bottle-fed babies; the gain in weight, which 
diminishes with the age of the child, amounts to thirty-five 
grammes daily during the first month, 16.3 grammes during 
the third month, and 8.1 grammes during the sixth month. 
There are great variations in the weight increase, although the 
average gain is essentially the same as in breast-fed babies. 
Notwithstanding the greater number of calories supplied, the 



116 THE ARTIFICIAL FEEDING OF INFANTS. 

body weight of bottle-fed infants does not increase proportion- 
al ly as fast as that of sucklings. 

The proper food for strong children up to six months of 
age is milk diluted one-half or two-thirds, with sugar added; 
for weaker children milk diluted one-third, with cream and 
sugar added. Schmid-Monnard thinks that infants of low 
weight and delicate constitution assimilate proteids better than 
stronger infants, in whom the casein passes more or less un- 
digested through the intestinal tract. Even in the most dilute 
mixtures there are enough proteids, but not enough fat and 
sugar to supply the needs of the body. Whereas the nursing 
child takes in its first year three and a half kilogrammes of 
proteids, twelve kilogrammes of fat, and twenty kilogrammes 
of sugar, artificially fed babies get in their first six months 
five and a half kilogrammes of proteids, six and two-thirds 
kilogrammes of fat, and ten and a half kilogrammes of sugar, 
— enough proteids, but scarcely enough fat and sugar. 

Marfan 105 concludes, on the basis of his clinical experience, 
that healthy infants can, as a rule, digest pure sterilized cow's 
milk after the fourth to the fifth month; before that time 
even the purest milk should not be given undiluted. He has 
found that healthy infants under four or five months, who are 
fed on pure cow's milk, fall into one of three classes : 

I. The first and smallest class show signs of chronic gastro- 
intestinal inflammation with general atrophy and cachexia. 

II. The second class show no anomalies, especially those 
infants who have had the breast for the first few weeks. 

III. The third and largest class, which includes those in 
especial who have received nothing but pure cow's milk since 
birth, are apparently well, but on examination we find them 
suffering from constipation; the stools are pasty and putty- 
colored, and constipation alternates with diarrhoea; vomiting 
is frequent. It is probable that this dyspepsia is due to a mild 
form of gastro-enteritis (pure cow's milk dyspepsia). Variot 
advises that cow's milk should be diluted three or four times 



MODERN METHODS OF INFANT FEEDING. 117 

during the first weeks of life; a little sugar should be added. 
Gauehas believes that cow's milk should be diluted during the 
first four or five months of the child's existence. 

The method which Marfan has followed during recent years 
consists in the use of milk diluted with boiled water to which 
enough sugar is added to make a teu per cent, solution. For 
the first five or six days the mixture should be half milk and 
half sugar solution; from this time up to four or five months 
the mixture should be two-thirds milk and one-third sugar 
solution; after this time Marfan tries to give whole milk, 
with enough sugar added to bring the sugar percentage up 
to six. If digestive disturbances arise, he dilutes the milk 
three or four times with sugar-water. The milk should be 
sterilized at 100° C. in small bottles on the "bain-marie/' after 
mixing with sugar-water. 

Marfan does not consider that it is necessary to reduce the 
casein to the proportions found in mother's milk, the only 
object of dilution being to render the casein more digestible. 
By adding ten per cent, sugar solution we can to a certain 
extent supply the deficit in fat. His mixture of two parts 
of milk and one part of ten per cent, sugar solution contains 
2.2 per cent, casein, seven per cent, sugar, and 2.4 per cent, 
fat, with O.-i per cent, salts. By giving a mixture of this 
strength we avoid overcharging the stomach with too great a 
quantity of diluted milk. It is important to use a milk which 
is rich in fat (from 3.8 to four per cent.). Marfan doubts the 
advisability of adding salt, sodium bicarbonate, or lime-water. 
Salt is only useful in certain cases of indigestion, to combat 
lientery, anorexia, and constipation. Milk should not be alka- 
lized before sterilization, and Marfan considers it superfluous 
except in certain cases of gastric disturbance. His only ob- 
jection to this method is that the gain in weight is slightly 
less than in the case of breast-fed infants. 

Centrifugation modifies the fat of milk so as to render it 
difficult of digestion. This explains its failure in cases of 



118 THE ARTIFICIAL FEEDING OF INFANTS. 

digestive disturbances. Marfan advises that the feedings should 
always be three hours apart to allow of perfect digestion. 

Comby 229 advises that milk should be diluted in the follow- 
ing manner: 

First month One-half milk and one-half water. 

Second month . . . Two-thirds milk and one-third water. 

Third month Three-quarters milk and one-quarter water. 

Fourth month . . .Pure milk. 

To each one hundred and fifty cubic centimetres of the 
mixture he adds 4.5 cubic centimetres of sugar. Ordinary 
sugar or lactose may be used. Water is the best diluent. The 
mixture should not be too dilute, for in that case the child 
is likely to take too great a quantity in its efforts to get the 
amount of nourishment required. Of the alkaline diluents 
lime-water is the best. Comby believes in mixed feeding if 
the breast-milk is deficient. At six months the breast-milk 
almost always has to be supplemented. Panada may be used 
for weaning; it is made by thoroughly soaking toasted bread 
or well-cooked biscuit in water, adding butter and salt, and then 
boiling. It may be thickened with egg. Kacahout, salep, and 
phosphatine salieres (a mixture of rice, tapioca, potato, and 
arrowroot in equal parts plus cocoa, sugar, and phosphate 
of lime; of the latter ingredient 0.20 gramme to each five 
cubic centimetres of gruel) may be used to thicken milk, 
broths, and gruels, and are well liked by children. Arrow- 
root is poor in albuminous substances; it should not be 
employed early, as indigestion, anaemia, scurvy, etc., result. 
These preparations are to be used in weaning, always with 
fresh milk. 

Budin 23 advises the use of pure cow's milk, sterilized at 
100° C, kept in separate bottles, and used within twenty-four 
hours. Occasionally it is necessary to dilute milk with water 
for infants under two months; or one can try Vigier's Hu- 



MODERN METHODS OF INFANT FEEDING. 119 

manized Milk, Backhaus Milk, or Gaertner's Milk. Yariot also 
recommends the employment of sterilized whole milk. 

Boissard 21 uses humanized milk in which the casein per- 
centage is reduced to 1.7 instead of 3.6; this is accomplished 
by the same method which Gaertner employs in preparing 
Mother's Milk. The milk should be heated to 38° C. and thor- 
oughly mixed by shaking before it is used. The author thinks 
that pasteurization at home would give more satisfactory re- 
sults than sterilization, since the former does not alter the 
taste or composition of the milk. 

Jacobi. 76 For the purposes of nutrition nature allows great 
latitude, since the mother's milk constantly changes from one 
minute to another, from morning till night, depending on her 
diet, state of health, menstruation, and stage of lactation, — 
and still the baby thrives ! Thus there is no sameness in human 
milk, and for that reason no possibility of arranging a perfect 
and uniform substitute for every kind of it. 

The caseins of mother's milk and cow's milk differ both chem- 
ically and physiologically. These differences have been studied 
extensively since Hammarsten first wrote thirty years ago, 
but to this moment it is not clear whether the albuminoid 
which is found besides casein is coordinate to it or derived 
from it. There are some modern observations which seem to 
prove conclusively that the caseins of different animals cannot 
be identical any more than are their blood-cells. Wassermann 
and A. Schtitze found that by injecting different animals daily 
with sterilized cow's milk for a fortnight, their blood-serum 
acquired the property of coagulating the proteids of cow's milk, 
but not those of another animal. Similarly, other milks exer- 
cised a specific coagulating effect upon their own proteids. 

There need be no better proofs of the differences between the 
caseins of different milks; every animal has its own specific 
milk adapted to the wants of its own offspring, and the belief 
that one milk can be substituted for another is a mistake. 



120 THE ARTIFICIAL FEEDING OF INFANTS. 

In regard to various methods of feeding, Jacobi asks whether 
it is true that iron-clad rules as to the composition of a sub- 
stitute are to the point or justified. In his opinion, only one 
great progress has been made in infant feeding these dozens 
of years, — namely, the more or less universal introduction of 
the practice of heating cow's milk and all other substances 
employed in infant feeding. 

In Jacobi's experience with Laboratory Milk, many infants 
thrive on it for a certain time, for the mixture is sterilized in 
single feeding-bottles holding prescribed quantities, but very 
many become more or less rachitic. He has frequently seen 
mild forms of craniotabes which required the addition of ani- 
mal food, phosphorus, etc. 

There can be no doubt that the end aimed at by Rotch 
is partly obtained by securing a reliable and approximately 
fresh milk, and by sterilizing it in small portions. In that he 
has performed, with Coit and others, most valuable educational 
and missionary work. 

The dilutions Jacobi employs vary from four to six parts 
of diluent to one part of milk for the new-born, down to equal 
parts at six months. In general he believes that the propor- 
tion of casein should not exceed one per cent, during the early 
months. 

Jacobi prefers cane-sugar to lactose in the preparation of 
his mixtures, since it is not so easily transformed into lactic 
and other acids. The identity of the lactose in mother's milk 
and cow's milk has not been proved, and the lactose of the 
market is quite often impure. That alone makes it desirable 
or advisable to substitute cane-sugar, if this affords the same 
advantages. 

After eight-tenths of one per cent, of the lactose contained 
in whole milk is changed in the stomach into lactic acid, its 
production ceases. Ordinarily this limit is reached when about 
one-fourth of the milk-sugar has been so converted. But 
if at that time lactic acid be neutralized by an alkali, more 



MODERN METHODS OF INFANT FEEDING. 121 

milk-sugar is changed into lactic acid. Therefore it appears 
that in every preparation of cow's milk selected for the use 
of the infant there is enough milk-sugar to supply the needs 
of the digestive processes. 

Finally, he adds, the antifermentative action of lactic acid 
displayed during the putrefaction of albuminoids is shared 
by other sugars and by starch, and Miura has proved that the 
small intestines of the foetus and new-born contain an inverting 
ferment which renders possible the absorption of cane-sugar. 
To repeat, a milk mixture which contains twenty-five per cent, 
of milk will furnish enough milk-sugar for the purposes of 
lactic acid production and of digestion. 

The proportion of fat in an infant's diet should never ex- 
ceed that found in mother's milk. According to Heubner, 
5.9 per cent, (in the breast-fed infant), 5.3 per cent, (in the 
infant fed on cow's milk), and fifteen per cent, (in infants 
with weak digestion) of the fat introduced in the food is ex- 
pelled undigested. If so much is expelled unchanged, Jacobi 
does not consider that the addition of cream to the milk mix- 
ture is quite a sine qua non. " In the face of these data, cow's 
milk fat is added to infant food equally in winter and in sum- 
mer, while the Esquimaux of the cold climate have told us 
long ago that it is they that require fat, and the ancient He- 
brews of the torrid zone that it should be prohibited in broiling 
climates or seasons. Nor has the frequency of (Biedert's) 
fat diarrhoea, which has been noticed even in infants nursed 
by their own mothers, been a warning." Moreover, the fat 
of cow's milk differs from that of mother's milk. The latter 
has more oleic acid and less volatile acids than cow's milk. 
Mother's milk contains its fat in finer emulsion and has from 
two to four times as many fat-globules as are found in an 
equally fat cow's milk (Schlossmann). It is reasonable to 
assume that such fine fat-globules may be absorbed directly 
through the epithelia of the intestinal villi. The fat of cow's 
milk, before it is used, undergoes changes : when raised by 



122 THE ARTIFICIAL FEEDING OF INFANTS. 

the gravity process, it is apt to acidulate ; when sterilized and 
centrifugated, it is changed chemically and physically; when 
frozen, it separates from the milk and does not mix again. 
All these facts have led Jacobi to reduce rather than to increase 
the fat of cow's milk used for infant feeding. 

Jacobi is a firm believer in dilution, and has found that 
" there is not a more frequent cause of dyspepsia, except ex- 
cessive summer heat and senseless amounts of pasty amylaceous 
foods, than undiluted cow's milk in the well and the sick 
infant." The objections made on the ground that large 
amounts of food may cause gastric dilatation, he believes, are 
theoretical. The rapid action of the almost vertical stomach 
and the rapid absorption from it and from the intestine of 
fluids containing salts and sugar render gastric dilatation " very 
improbable — probably impossible." Water does not act like 
bulky indigestible food, and diabetics may drink daily from 
five to ten litres of it for years without dilatation of the stom- 
ach from that cause. Furthermore, a great quantity of water 
is needed to assist in pepsin digestion. In artificial digestion, 
albumin often remains unchanged until large quantities of 
acidulated water are supplied. Peptones require water to 
facilitate their solution and absorption; moreover, it is cer- 
tainly true that large amounts of water passing through the 
kidneys reduce the danger of uric acid infarcts, the results 
of which are gravel, renal calculus, and nephritis. 

Where plain water is to be used, it will generally give greater 
satisfaction if it has previously been boiled, in the case of 
very young infants, even if there be no apparent urgency 
for it. 

Dilutions with plain water may seem to be harmless; in 
many instances children thrive on them. More, however, only 
appear to do well, for increasing weight and obesity are not 
synonymous with health and strength. A better way to dilute 
cow's milk, and at the same time to render its casein less 
liable to coagulate in large lumps, is to add decoctions of the 



MODERN METHODS OF INFANT FEEDING. 123 

cereals. Those which contain the least starch are to be pre- 
ferred^ — barley where there is a tendency to diarrhoea, oatmeal 
in cases of constipation. Schiller, Korowin, and Zweifel have 
proved that infants, even from birth, can transform small 
amounts of starch into sugar by the action of the saliva. Be- 
ginning with the fourth week, the pancreatic secretion also 
possesses diastatic properties. " Not only does amylum save 
feeding with albuminoids (Voit), the excess of which leads 
so easily to intestinal putrefaction; not only is it, together 
with other carbohydrates, the principal source of muscular force 
in general and of the heart in particular (mainly in the acute 
diseases and probably better than alcohol) ; but it (amylum) 
also acts as a direct intestinal antiseptic." 

The physiological effect of sodium chloride is very important, 
no matter whether it is directly introduced through the woman's 
milk or added as a condiment to cow's milk; the latter con- 
tains more potassium than sodium, and ought never to be 
given without the addition of table salt. There is no better 
protection to the epithelia and cell fluids than sodium chloride. 
Excretion and secretion are to a great extent rendered safe 
by it; it serves directly as an excitant to the secretion of 
the gastric glands and facilitates digestion. Another very im- 
portant fact is this : the addition of sodium chloride prevents 
the solid coagulum of milk by either rennet or gastric juice. 
Therefore it should always be added to mixtures of cow's milk, 
and should also be given in cases nourished on the breast, if 
the mother's milk behaves like cow's milk in regard to solid 
curdling. Where decoctions of cereals are used, the percentage 
of salt should be much higher. 

It is to be questioned how much alkalization can be ef- 
fected by the addition of lime-water in five per cent, strength 
(as commonly advised). At 59° F. it contains 0.17 per cent, 
of lime, in rising temperatures less, and at the boiling point 
0.13 per cent. An experiment with good cow's milk showed 
that lime-water failed to overcome acidity. 



124 THE ARTIFICIAL FEEDING OF INFANTS. 

To render milk distinctly alkaline with sodium bicarbonate 
may be a grave error. The very bacilli which, with their spores, 
resist boiling to an unusual degree thrive best in an alkaline 
milk. 

The new-born should have its milk boiled, sugared, salted, 
and mixed with from four to five times its amount of barley- 
water. At six months give equal parts. Gum arabic and gela- 
tin are also useful, not only as diluents but also as nutrients. 
Xo single method is to be considered infallible; each case has 
its own requirements. 

After boiling, milk should be kept in a clean bottle containing 
from three to six ounces, filled to the cork and inverted in a 
cool place. Before being used, it should be heated on a water- 
bath. By repeating this heating of the whole amount several 
times a day, fermentation will be retarded and the digestibility 
of the milk improved. 

Starr. 133 Success in hand feeding depends on the adminis- 
tration as well as on the proper modification of the cream 
and milk mixtures, — i.e., care of the bottle, nipples, etc. The 
separate preparation of each meal is important, as changes 
occur in the food if it is all mixed at the same time. The 
child should occupy a half reclining position when nursing, 
to prevent air from being swallowed, and from five to fifteen 
minutes should be allowed for each meal. Even the youngest 
infants require water several times a day, and the necessity 
increases with age. During the summer water cooled with 
ice may be allowed without harm; at other times water should 
not be too cold. 

To render cow's milk as nearly like human milk as possible 
it is necessary to reduce the percentage of casein, to increase 
the proportion of fat and sugar, and to overcome the tendency 
of the casein to coagulate in large masses. To accomplish this 
we dilute with water, add fat in the form of cream, and either 
cane-sugar or lactose. The latter is greatly to be preferred to 
cane-sugar, as it is less apt to ferment and contains the salts 



MODERN METHODS OF INFANT FEEDING. 



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126 THE ARTIFICIAL FEEDING OF INFANTS. 

of milk, which are of nutritive value. Starr recommends the 
use of lime-water, one to three, as it causes clotting of the 
casein to take place more slowly and in smaller masses. A 
saccharated solution of lime is even better than lime-water. 
Instead, from two to four grains of sodium bicarbonate may 
be used to each bottle. 

Starr believes that barley-water and other attendants act 
mechanically by preventing the agglutination of casein par- 
ticles in large masses. The former, to be efficient, should be 
used in the same proportion and in place of water. Gelatin 
may also be used. Except when employed as mechanical dilu- 
ents, starches should not be used before the fourth month, 
since they differ so materially from human milk in composition 
that they are apt to lead to digestive disturbances. 

At the second, third, and fourth meals two teaspoonfuls of 
a reliable infant's food may be added, the milk-sugar being 
omitted. Baked wheat or barley flour may be used instead 
if there is a tendency to diarrhoea. 

We may give as substitutes for cow's milk equal parts of 
veal broth and barley-water, or of whey and barley-water plus 
a small amount of lactose ; also a teaspoonful of raw beef juice 
diluted. Sometimes it is sufficient in cases of indigestion to- 
wards the end of the first year to reduce the strength of the food 
to that suited for a child from two to three months younger. 

Starr. 135 " Laboratory Milk is theoretically the most per- 
fect substitute for normal human milk that science has yet 
devised. But unfortunately clinical experience, in my own 
practice at least, does not bear this theory out." The following 
is a generalization of the results of over two years' study of the 
use of Laboratory Milk in substitute feeding. 

I. Three cases could be termed satisfactory, — i.e., healthy 
infants continuously fed on Laboratory Milk from shortly after 
birth to the time of beginning mixed diet. 

II. Sixteen cases were partially satisfactory, — i.e., infants in 
whom Laboratory Milk was used for some time — from six 



MODERN METHODS OF INFANT FEEDING. 127 

months to a year — without producing active illness, but gradu- 
ally inducing unhealthy conditions which necessitated a change 
of food. 

III. Thirty-five cases were unsatisfactory, — i.e., infants in 
whom Laboratory Milk had to be discontinued on account of 
the onset of some acute disorder of undoubted dietetic origin. 

The unhealthy conditions referred to in the second class 
presented a very uniform group of symptoms, — namely, pallid, 
dry skin ; dry, lustreless hair ; soft, flabby muscles ; indifferent 
appetite; inactive, not decidedly constipated, bowels; clay- 
colored evacuations; light-colored urine; listlessness and dis- 
inclination to play; peevishness and restless sleep — in a word, 
the features of malnutrition. With the flabbiness there is not 
always emaciation, but the two conditions are often asso- 
ciated. 

Although scurvy is an exceptional result of laboratory feed- 
ing, Starr has personal knowledge of one undoubted case in 
which orange juice removed the symptoms, but where the child 
did not thrive until placed on a domestic mixture. 

Why should a food which so nearly approaches breast-milk in 
its composition, which is uniform in its make-up, sterile, and 
easily and accurately modified to meet digestive emergencies, — 
why should it fail when put to a clinical test? Starr thinks 
that it is due to the destruction of the natural fat emulsion 
by the use of the separator. In some way the digestibility 
of the proteids is diminished, thus giving rise to malnutrition 
or to irritative diarrhoea. Starr has never seen an infant 
below the age of ten months who could tolerate a laboratory 
mixture containing over one and a half per cent, proteids, 
and has often encountered cases where at the age of two months 
or more a percentage of 0.50 proteids was not digested. " When 
unseparated milk is the basis of our mixture, and we have a 
natural emulsion to deal with, the proteids are much more 
easily digested, so that a badly nourished child of ten months, 
in whom Laboratory Milk percentage cannot be forced higher 



128 THE ARTIFICIAL FEEDING OF INFANTS. 

than 1.5 proteids, will easily digest and grow strong upon a 
domestic mixture containing proteids 2.97 per cent., sugar 
4.94 per cent., and fat 3.75 per cent/' Of course the same care 
must be taken in home modification to secure pure, clean milk 
and cream from healthy, well -tended cows. Pasteurization 
can be carried out at the home, and accurate measurements 
of the food quantities and cleanliness of the vessels and bottles 
can be obtained. The daily variations in the milk and cream 
Starr considers a minor detail of questionable importance when 
compared with the destruction by the separator of the chemi- 
cal combinations present in milk. We certainly should not 
sacrifice everything to chemical accuracy. 

He does not wish to be understood as condemning Laboratory 
Milk absolutely. Its introduction has greatly advanced sub- 
stitute infant feeding by drawing attention to the importance 
of cleanliness and accuracy in the quantity and composition 
of milk formulae. It has placed the whole question on a 
higher scientific plane than had ever been reached before. 

Holt. 183 The following principles form the basis of all 
methods for the scientific feeding of infants : 

" I. Mother's milk is not only the best, it is the only ideal 
infant food. 

" II. Any substitute should furnish the same constituents, — 
namely, fat, sugar, proteids, salts, and water; furthermore, 
they should be in about the same proportions as they exist in 
woman's milk. 

" III. As nearly as possible the different constituents should 
resemble those of mother's milk both in their chemical compo- 
sition and in their behavior to the digestive fluids. 

" IV. These conditions are fulfilled only by fresh milk from 
some other animal. 

" The central thought of the American or percentage system 
of feeding is to consider the different elements of the food 
separately and to adapt their proportions to the child's diges- 
tion. ... It aims to discover the proper proportion of fat, 



MODERN METHODS OF INFANT FEEDING. 129 

sugar, and proteids and the best methods of gradational in- 
crease for healthy infants with normal digestions, and also to 
discover for those with abnormal or feeble digestion the com- 
binations best suited to the individual conditions." 

Since one element of the milk alone may be at fault, it is 
often sufficient to reduce its proportion without reducing the 
proportions of all the elements or entirely giving up the use 
of milk. 

Fat. — The average amount of fat which a healthy infant 
can digest is one per cent, on the second day, two per cent, 
at one week, increased to three per cent, at three or four weeks 
and to four per cent, at four or five months. 

Sugar. — It is seldom necessary to reduce the sugar per- 
centage below five or to exceed seven, the quantity present in 
mother's milk. As the sugar in milk is simply lactose in solu- 
tion, it is only necessary to calculate the amount required to 
bring the percentage up to that desired. The milk-sugar must 
be filtered through absorbent cotton if it contain impurities, 
and dissolved in boiling water ; it must be prepared fresh every 
day in summer and every second day in winter. If good milk- 
sugar cannot be obtained, cane-sugar may be substituted; but 
little more than half the quantity is needed as compared with 
milk-sugar on account of its greater sweetness and greater 
liability to ferment in the stomach. In exceptional cases cane- 
sugar or maltose is better borne than lactose. 

Proteids. — The proteids give the most trouble to the infant's 
digestion. In the first few days their proportion should be 
reduced to from 0.33 to 0.50 per cent. The secret of success 
is to reduce the proteids at the start to such proportions as 
the infant can easily digest, then gradually to increase the 
quantity. At the end of the first month the average child can 
take one per cent., from two to three months one and a half 
per cent., and from four to five months two per cent. This 
reduction in proteids is effected by dilution with water. Except 
to start with too high proteids, no more common mistake is 



130 THE ARTIFICIAL FEEDING OF INFANTS. 

made than to continue too long with too low proteids. Anae- 
mia, malnutrition, and not infrequently scurvy result from 
this practice. 

Diluents. — Barley-, rice-, and oatmeal-water are convenient 
forms in which starch may be added to the food of infants 
who are old enough to be able to digest it, — e.g., from seven 
to eight months. More diluted, they may be used to allay thirst 
when the stomach is irritable and all forms of milk must 
temporarily be withheld. Kice-water or barley-water is usually 
preferable when there is diarrhoea, and oatmeal-water when 
there is constipation. It is questionable whether barley-water 
is superior to plain water as a diluent; in some cases it cer- 
tainly seems to be useful. 

Salts. — Like the proteids, inorganic salts are in excess in 
cow's milk, and in nearly the same proportion, so that the 
dilution of the one causes that of the other. 

Reaction. — The acidity of cow's milk may be overcome by 
the addition of either lime-water or sodium bicarbonate. Of 
the former, one ounce is enough for twenty ounces of the milk 
mixture; of the latter, one grain to each ounce is sufficient. 
For very young infants it is often desirable to add twice as 
much lime-water. 

Milk-Laboratory. — The establishment of the milk-labora- 
tory is a great stride in advance in infant feeding, since it 
becomes possible to vary any one of the constituents of the 
food separately until the combination is reached which is 
suited to the infant's digestion. It is also a decided advantage 
to know that the child is getting exactly what has been ordered, 
and not to have to put up with the ignorance or carelessness 
of the mother or nurse who otherwise would prepare the food. 
The main objection to Laboratory Milk has been its expense. 
Holt does not consider that there is any difference in the 
digestibility of centrifugal and gravity cream. 

The following table represents the average percentages of 
proteids, sugar, and fat which the healthy infant can take: 



MODERN METHODS OF INFANT FEEDING. 



131 



Age. 


Fat. 
Per 
cent. 


Sugar. 
Per 
cent. 


Proteids. 
Per 
cent. 


Amount at 

each feeding. 

Ounces. 


No. of 

feedings in 
24 hours. 


Interval 
by day 

in hours. 


Premature infants .... 


1.0 


4.0 


0.25 


H 


12- 


18 


l-H 


First to fourth day .... 


1.0 


5.0 


0.3 


l-H 


6- 


10 


2-4 


Fifth to seventh day . . . 


1.5 


5.0 


0.5 


1-2 


10 




2 


Second week 


2.0 
2.5 
3.0 


6.0 
6.0 
6.0 


0.6 

0.8 
1.0 


2-2J 
2-3* 
2^-4 


10 

10 

9 




2 


Third week 


2 


Fourth to eighth week . 


2J 


Third month 


3.0 
3.5 


6.0 
7.0 


1.25 
1.5 


3-5 


8 

7 




2£ 


Fourth month 


3 


Fifth month 


3.5 


7.0 


1.75 


4-6 


7 




3 


Sixth to tenth month . . 


4.0 


7.0 


2.0 


•5-8 


6 




3 


Eleventh month 


4.0 


5.0 


2.5 


6-9 


5 




4 


Twelfth month 


4.0 


5.0 


3.0 


7-9 


5 




4 


Thirteenth month 


4.0 


4.5 


3.5 


7-10 


5 




4 



Ho^ie Modification of Milk. 

Holt considers that three and a half per cent, proteids is 
more nearly the correct average of the mixed milk of a herd 
than fonr per cent., the average ordinarily given. The follow- 
ing table, based on analyses by Adriance and others, represents 
pretty accurately the composition of creams of different den- 
sity : 



Fat 

Sugar. . , 
Proteids , 
Salts . . . 



I. 


II. 


III. 


IV. 


v. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


Per cent 


4.00 


8.00 


12.00 


16.00 


20.00 


4.50 


4.35 


4.20 


4.05 


3.90 


3.50 


3.40 


3.30 


3.20 


3.05 


0.75 


0.70 


0.65 


0.60 


0.55 



Since in most modifications of milk the fat must be con- 
siderably higher than the proteids, it may be introduced by 
the addition of cream or by using top milk. 



132 THE ARTIFICIAL FEEDING OF INFANTS. 

A series of experiments (one hundred and ten analyses) at 
the Walker-Gordon farm have shown that if mixed milk be 
immediately bottled and cooled, after four hours the upper 
fourth will contain nearly all the fat, which will rise as cream, 
and the upper layers will have nearly the same percentage of 
fat whether the milk has stood for four hours, for eight hours, 
or overnight. 





After four hcmrs. 


Aftei 


• eight hours. 


Overnight. 




Per cent, of fat. 


Per cent, of fat. 


Per cent, of fat. 


Upper four ounces .... 


20.50 




21.25 


22.00 


Second four ounces . . . 


6.00 




6.50 


6.50 


Third four ounces 


1.50 




1.40 


1.00 


Fourth four ounces . . . 


1.20 




1.00 


0.30 


Fifth four ounces 


1.00 




1.00 


0.05 



Fat. 
>r cent. 


Sugar. 
Per cent. 


Proteids. 
Per cent 


7 


4.40 


3.40 


10 


4.30 


3.30 


13 


4.15 


3.25 


16 


4.05 


3.20 



Using standard milk containing four per cent, fat, we can 
secure approximately the following results : 



Sixteen ounces, or the upper half, furnish . 
Eleven ounces, or the upper third, furnish . 
Eight ounces, or the upper fourth, furnish . 
Six ounces, or the upper fifth, furnish 



If the milk we are using is rich in fat (five per cent, or 
over), from two to three ounces more should be removed for 
each formula; if it is poor in fat (from three to three and 
a half per cent.), about two ounces less than the amount speci- 
fied should be used. 

The three formulae which are most useful are : ( 1 ) Those 
where the fat is three times the proteids. (2) Those where 
the fat is twice the proteids. (3) Those where they are about 
equal. 



MODERN METHODS OF INFANT FEEDING. 133 

Series A. — Eatio of fat to proteids, three to one. 

Primary formula (ten per cent, milk) : fat ten per cent.,, 
sugar 4.30 per cent., proteids 3.30 per cent. Obtained (1) 
by using the upper one-third of bottled milk, or (2) by 
using equal parts of milk (four per cent.) and cream (six- 
teen per cent.). 

Derived Formula giving Quantities for Twenty-Ounce 
Mixtures. 

Milk-sugar one ounce. 

Lime-water one ounce. 

Boiled water to make twenty ounces. 



I. With one ounce of ten per cent, milk . . 

II. With two ounces of ten per cent, milk . 

III. With three ounces of ten per cent, milk 

IV. With four ounces of ten per cent. milk. 
V. With five ounces of ten per cent, milk . . 

VI. With six ounces of ten per cent, milk . . 

VII. With seven ounces of ten per cent, milk 



To make twenty-five ounces, add one-fourth more of all the 
ingredients; to make thirty ounces, add one-half more. 

Series B. — Eatio of fat to proteids, two to one. 

Primary formula (seven per cent, milk) : fat seven per 
cent., sugar 4.40 per cent., proteids 3.40 per cent. Obtained 
(1) by using the upper half of bottled milk, or (2) by using 
three parts milk (four per cent.) and one part cream (sixteen 
per cent.). 

Derived formulae giving quantities for twenty-ounce mix- 
tures. Amount of milk-sugar, lime-water, and water as above. 



Fat, 


Sugar. 


Proteids 


Per cent. 


Per cent. 


Per cent 


. 0.50 


5.20 


0.17 


. 1.00 


5.40 


0.33 


. 1.50 


5.60 


0.50 


. 2.00 


5.85 


0.66 


. 2.50 


6.05 


0.83 


. 3.00 


6.25 


1.00 


. 3.50 


6.50 


1.20 



134 THE ARTIFICIAL FEEDING OF INFANTS. 

Fat. Sugar. Proteids. 

Per cent. Per cent. Per cent. 

I. With one ounce of seven per cent. milk. . 0.35 5.20 0.17 

II. With two ounces of seven per cent, milk . 0.70 5.40 0.35 

III. With three ounces of seven per cent, milk 1.05 5.60 0.52 

IY. With four ounces of seven per cent. milk. 1.40 5.80 0.70 

V. With five ounces of seven per cent. milk. 1.75 6.00 0.87 

VI. With six ounces of seven per cent, milk . . 2.10 6.20 1.05 

VII. With seven ounces of seven per cent, milk 2.45 6.45 1.22 

VIII. With eight ounces of seven per cent, milk 2.80 6.70 1.40 

IX. With nine ounces of seven per cent. milk. 3.15 6.90 1.55 

X. With ten ounces of seven per cent, milk . . 3.50 7.10 1.75 

XI. With eleven ounces of seven per cent, milk 3.85 7.30 1.92 

XII. With twelve ounces of seven per cent, milk 4.15 7.50 2.07 

Series C. — Ratio of fat to proteids, eight to seven. 

Primary formula (plain milk) : fat fonr per cent., sugar 
4.50 per cent., proteids 3.50 per cent. 

Derived formulae giving quantities for twenty-ounce mix- 
tures. Amount of milk-sugar, lime-water, and water as above. 



I. With two ounces of four per cent, milk 

II. With four ounces of four per cent, milk, 

III. With six ounces of four per cent, milk . , 

IY. With eight ounces of four per cent, milk 

Y. With ten ounces of four per cent. milk. , 

YI. With twelve ounces of four per cent, milk 2.40 

VI I. With fourteen ounces of four per cent, milk 

VIII. With sixteen ounces of four per cent, milk 

When the formulae contain from one-half to three-fourths 
milk, three-fourths of an ounce of milk-sugar is sufficient for 
each twenty ounces; if more milk is used, add only half an 
ounce of lactose. 



Fat. 


Sugar. 


Proteids, 


er cent. 


Per cent. 


Per cent. 


0.40 


5.40 


0.35 


0.80 


5.80 


0.70 


1.20 


6.20 


1.05 


1.60 


6.70 


1.40 


2.00 


7.10 


1.75 


2.40 


7.60 


2.10 


2.80 


8.10 


2.45 


3.20 


8.50 


2.80 



MODERN METHODS OF INFANT FEEDING. 135 

The first year may be divided into three feeding periods: 
the first, from birth to the end of the third or fourth month: 
the second, from this time to the end of the tenth month: 
the third, the rest of the first year. During the first period 
the best results are obtained when the fat is three times the 
proteids: during the second period, when the fat is twice the 
proteids; during the third period, when the two are nearly 
equal. 

General Rules for varying Milk Percentages. — Xo sched- 
ule for infant feeding can be followed with absolute regularity, 
since in each case the individual factors must be taken into 
account, such as the age. weight, condition of the digestive 
organs, etc. An infant that at four months weighs as much as 
the average infant at eight months will usually be able to take 
a quantity of food and also the percentage advised for the 
latter age. Again, there are many cases in which the per- 
centages of the milk must be increased more slowly than the 
schedule, but the same gradational steps of increase may ad- 
vantageously be followed with all cases. 

During the first two or three weeks of life no material gain 
in weight is to be expected while the infant is taking mix- 
tures with very low percentages. This condition may be con- 
sidered entirely satisfactory, provided the child is comfortable 
and shows no signs of indigestion: the strength of the food 
may gradually be increased with the demands of the child's 
appetite, and gain in weight will usually follow after a short 
time. " Xothing is easier than to derange the organs ( of 
digestion) during the first weeks by too high percentages, and 
such disturbances, even though they appear trivial, often con- 
tinue for many weeks." 

A caution is necessary against changing the formula? too 
frequently, since it is not possible to determine the infant's 
ability to digest a certain mixture short of at least two days. 

Special Symptoms. — The frequent regurgitation ( often one 
or two hours after feeding) of sour curdled milk or a watery 



136 THE ARTIFICIAL FEEDING OF INFANTS. 

fluid is usually an indication that the proportion of fat is 
too high. The first indication is to reduce the amount of fat ; 
other modifications which may be useful are to give double 
the amount of lime-water (ten per cent.) or to reduce the 
sugar percentage. It is important that the food be taken 
slowly, that the child be kept perfectly quiet after feeding, 
and that the intervals between feedings be longer than in the 
case of good digestion. 

Constipation during the first weeks of life, unless associated 
with manifest discomfort on the part of the child, should be 
disregarded, especially if the odor and color of the discharges 
are nearly normal. It is a mistake to increase the fat per- 
centage rapidly, since in a few days, when the proportions 
of the proteids and the fat are gradually increased according 
to the schedule, this form of constipation will pass away. 
" Anything higher than three per cent, of fat during the first 
four or five weeks almost always works badly; over four per 
cent, at any time during the first year can seldom be long 
continued without disturbing digestion." If constipation per- 
sists with these percentages, it is better to adopt other meas- 
ures for its relief than to further increase the fat. " The 
habitual colic of early infancy is almost invariably due to too 
high proteids, and rarely occurs when percentages as low as 
those above advised are given." 

" The appearance of curds in the stools is usually associated 
with colic and constipation; it is commonly due to too high 
proteids or to inability to digest the proteids given, even though 
the percentages are not high." Loose green or yellowish-green 
stools of a sour odor are sometimes caused by too high a per- 
centage of sugar, but more often by an excess of fat. There 
are usually from two to five stools a day resembling thin 
scrambled eggs. The small yellowish masses are often mistaken 
for curds. Stools such as those described are often seen in 
nursing infants as well as in those artificially fed, and the 
condition is not incompatible with steady and regular gain in 



MODERN METHODS OF INFANT FEEDING. 137 

weight. After it has persisted any length of time mucus is 
regularly present and an intractable intestinal catarrh may 
be produced. Large dry, white, or gray stools, which are often 
smooth, are generally due to an excess of fat. They have 
usually a peculiarly foul odor owing to the presence of fatty 
acids, and may be distinguished from curds by their solu- 
bility in ether and by their burning readily with the odor of 
butter. 

Feeding of Difficult Cases. — These cases include those 
infants who do not gain in weight (or whose gain is irregular. 
— Editors) and who habitually suffer from indigestion. The 
great majority result from previous improper feeding or equally 
improper nursing. " These cases are serious, since in most of 
them nothing can be accomplished without close and continuous 
personal observation. They do not tend to right themselves, 
and the infant's life is often sacrificed as the result of bad 
management." In the management of such a case we must 
not only ascertain the previous methods of feeding, but also 
investigate thoroughly the way in which the food has been 
prepared and administered (the condition of the nipples and 
bottles, the time between meals, cleanliness, etc.). 

Although some children do better with shorter intervals and 
smaller quantities, generally speaking, the intervals should be 
longer than in health. It is seldom wise to make them less 
than three hours for young infants or less than four hours 
for those who have passed the eighth or ninth month. When 
symptoms make a reduction in the food necessary, whether in 
quantity or strength, it should in most cases be radical to 
produce any decided effect. On the other hand, in increasing 
either the strength or the quantity of the food, the changes 
must be made very gradually, lest we overtax the sensitive 
digestion. 

" In troublesome protracted cases it is better, as a rule, 
to go to the opposite extreme from that which has previously 
been tried ; large feedings should take the place of small feed- 



138 THE ARTIFICIAL FEEDING OF INFAI\ T TS. 

ings, long intervals of short, and a stronger food may succeed 
one which is very dilute." 

An infant who has been long fed on farinaceous foods will 
probably improve when these are stopped entirely and suitable 
percentages of cow's milk are given. On the other hand, it 
may be necessary temporarily to withdraw milk in any form. 
" Such a course is often better than wasting time in juggling 
with fractional milk percentages when one or two intelligent 
trials have been entirely unsuccessful." 

In modifying milk for difficult cases, it is rarely necessary 
to reduce the sugar below four per cent. ; it should never be 
given above seven per cent. It is not often that the fat can 
be raised above three per cent, in cases of feeble digestion, 
even when they are over six months old. For younger infants 
" two per cent, is as much as it is wise to give, if there is any 
disposition to vomiting or regurgitation. Where such symp- 
toms are prominent, it may be necessary for a time to reduce 
the fat to one and a half or even to one per cent." Infants 
suffering from marasmus have a special difficulty in digesting 
the fats, while it is a common practice to give them in large 
proportions. 

In no class of cases is it more important to begin with low 
percentages of proteids than in those with naturally feeble 
powers of digestion. Disturbance is pretty sure to result if 
we begin by administering one or two per cent, of proteids 
to a very young infant. On the other hand, if we begin with 
0.33 or 0.50 per cent, proteids and gradually increase, there is 
seldom any trouble. 

In dealing with infants whose digestions have already been 
upset, " it is usually wise to begin by reducing the percentage 
of the disturbing element — fat or proteids — to a point where 
the child's most obvious symptoms of disturbance disappear, 
and then gradually but very slowly to increase, but to go no 
faster than the child's digestion will warrant, regardless of 
his appetite." It is impossible to feed these cases like healthy 



MODERN METHODS OF INFANT FEEDING. 139 

children and equally impossible to tell in advance, until one 
lias tried, just what mixture will succeed. 

Holt believes that in some cases the addition of the cereal 
gruels to the milk is " of material assistance in the digestion 
of the milk proteids.' 7 He prefers those made from prepared 
flours which need only from twenty to thirty minutes' cooking. 
The strength should be one rounded tablespoonful to a pint 
of water. ee A caution should be given against using too large 
a quantity of plain or even dextrinized gruels, for in this way 
the flatulent intestinal indigestion among the children of the 
poorer classes is frequently produced." 

In some cases in which fat and proteids are very difficult of 
digestion, owing either to acute or chronic gastro-intestinal de- 
rangements, it may become necessary to give temporarily a food 
composed almost entirely of carbohydrates, either farinaceous 
or malted foods. This may be continued for from a few days to 
two or three weeks, according to the severity of the symptoms ; 
but we must return as soon as possible to a milk diet, beginning 
with the smallest proportions of milk, or whey, or even con- 
densed milk. 

For difficult cases during the second year, milk should be 
the principal diet, modified as for healthy infants from eight 
to twelve months younger than the patient under treatment. 
Peptonization may be required even when the percentage of 
casein is not high. The daily quantity should generally be 
somewhat larger than for a young healthy infant taking food 
of the same strength. The interval should never be shorter 
than three hours, and in many cases four hours are to be pre- 
ferred. 

Botch. 119 - 253 With regard to the problem of infant feeding, 
Botch remarks that " the present is a most opportune time to 
raise a note of warning against allowing our enthusiasm over 
any one especial theory to warp our better judgment. There 
will surely be a reaction which will relegate to its proper place 
every theory built upon single factors of the problem before 



140 THE ARTIFICIAL FEEDING OF INFANTS. 

us, and which is actually doing harm by keeping in the back- 
ground other theories which, each in its own sphere, as a 
significant part of the whole, may be of very great importance 
in the successful solution of the general problem. Our scien- 
tific knowledge and clinical investigations have not yet enabled 
us to follow nature exactly, and we therefore have not yet 
obtained an ideal method of substitute feeding. We must, 
nevertheless, go as far as the present state of our knowledge 
will allow, thus gaining a little ground every year, and we 
must be especially careful not to be led astray by the ficti- 
tiously brilliant results which are reported from time to time 
in favor of certain foods." 

The mortality resulting from the use of various infant foods 
always remains far above that from the employment of human 
breast-milk. 

Eotch is convinced that the choice of a suitable food is only 
part of the problem of infant feeding; we must not neglect 
to " investigate and carry out in detail" the other general 
factors, neglect of which has had much to do with our failures 
with substitute feeding in the past. 

" Assuming, then, that the average breast-milk is the safest 
standard for us to copy," we can at once select the milk of 
the cow as the most available substitute from which to ob- 
tain the elements of our artificial food. The milk of other 
animals may approach more nearly in its composition to that 
of human milk. Apart from the impossibility of obtaining 
it in sufficient quantity, however, any milk will require 
some modification, and "it is as easy to change the propor- 
tions of the different constituents to a great degree as to a 
small." 

The general factors which Eotch considers of such impor- 
tance in the preparation of an infant food may be tabulated : 

(1) A pure milk obtained from healthy cows, under proper 
hygienic precautions (see Chapter IX.). 

(2) An alkaline reaction, which usually requires the addition 



MODERN METHODS OF INFANT FEEDING. 141 

of an alkali, this being the only foreign element that it has 
been found necessary to employ. 

(3) Thorough dilution of the food with water, as is found 
in human milk. Eotch prefers plain water to decoctions of 
starch. 

(4) The use of lactose to increase the sugar content. Cane- 
sugar, which some authors prefer, seems to act as a preserva- 
tive in a concentrated form, as it is found in condensed milk ; 
but when it is diluted it ferments very readily. Milk-sugar 
undergoes no direct alcoholic fermentation, but quickly changes 
to lactic (possibly acetic) acid in the presence of nitrogenous 
ferments, while cane-sugar easily undergoes alcoholic fermenta- 
tion, but changes to lactic acid less readily than milk-sugar; 
cane-sugar, moreover, takes on butyric acid fermentation more 
readily than does milk-sugar. So far as is known, cane-sugar 
is merely a reserve and cannot be used directly for nutrition, 
for which milk-sugar may possibly have a direct value. Finally, 
reasoning from analogy, we should say that as milk-sugar is 
the only form of sugar found in the milk of mammals, it is 
there for some good purpose, and that it is needed for the 
accomplishment of some process which takes place after the 
food has been swallowed. 

(5) The proper modification of the fat and proteids of 
cow's milk to suit the needs of the individual case. 

(6) The avoidance of starch. As woman's milk does not 
under any circumstances contain starch, and as the function 
of converting starch is in the process of development during 
the first ten or twelve months of life, and should therefore 
not be taxed, Eotch believes that starch should not form part 
of the infant's food in the early months of life. 

(7) The greatest care to secure absolute cleanliness of the 
nursing-bottles and nipples; the latter should be renewed 
frequently. 

(8) The adoption of uniform intervals between the feed- 
ings. 



142 



THE ARTIFICIAL FEEDING OF INFANTS. 



(9) The amount of food to be given at each feeding must 
be carefully regulated according to the gastric capacity. Fre- 
quently this does not correspond with the weight of the infant, 
yet the weight is undoubtedly of the greatest importance in 
determining the proper amount of food to be given during the 
early months of life. At this time it is especially necessary 
to avoid stretching an organ so easily distensible as is the 
infant's stomach, so that it is wiser to give too little rather 
than too much food. 

The following table is based on measurements of a large 
number of infants' stomachs. 



General Rules for Feeding during the First Year. 
Day feedings begin at six a.m. and end at ten p.m. 



Age. 


Intervals 

of 
feeding. 


No. of 
feedings. 


No. of 

night 

feedings. 


Amount 
at each 
feeding. 


Total in 

twenty-four 

hours. 




Hours. 






Cc. 


Cc. 


One week 


2 


10 




30 


300 


Two weeks 


... . 2 


10 




45 


450 


Four weeks 


2 


9 




75 


675 


Six weeks 


2i 


8 




90 


720 


Eight weeks 


2| 


8 




100 


800 


Three months 


2% 


7 
7 






120 
135 


840 


Four months 


2£ 


945 


Five months 


3 


6 





165 


990 


Six months 


3 


6 





175 


1035 


Seven months 


3 


6 





190 


1140 


Eight months 


3 


6 





210 


1260 


Nine months 


3 


6 
5 






210 
255 


1260 


Ten months 


3 


1275 


Eleven months 


3 


5 

5 






265 

270 


1325 


Twelve months 


3 


1350 



Ssnitkin, in a series of careful investigations at the Chil- 
dren's Hospital at St. Petersburg, determined the amount of 



MODERN METHODS OF INFANT FEEDING. 143 

food required during the first months of life. He concluded 
that " the greater the weight the greater the gastric capacity/' 
To calculate the amount needed take t ^q of the initial weight 
of the infant and add one gramme to each day of life; for 
example, if the initial weight is three kilogrammes, T ^-g- of this 
will be thirty grammes. At fifteen days, therefore, give thirty 
plus fifteen, or forty-five grammes. 

Eotch considers that it is best to secure first of all the proper 
digestion of the food, even should there be no gain in weight, 
and then to increase the percentages of the different elements. 
Sometimes marked hunger requires a sudden increase in the 
quantity of food. This may be due to rapid growth of the 
infant's stomach, which in some cases is out of proportion 
to the age and size of the child. 

Milk-Laboratories. 

The long-felt desire that the subject of infant feeding should 
be reduced to a more exact system has led Eotch to give his 
professional assistance to the establishment of milk-laboratories, 
which have become so well known.* They enable the physician 
to prescribe the infant's food exactly as he prescribes its medi- 
cine. In this way, when lacking in success, he can be sure 
that it is the fault of the food he is giving, and not because 
the food has varied from what he supposed he had ordered. 
Xo one mixture will in all cases prove successful, but a great 
variety in the percentages of the different elements of the milk 
will be needed in substitute feeding just as they already exist 
in maternal feeding. This explains the diversity of results 
obtained in the past with the same food by different practi- 
tioners. 

The laboratory should be situated in a healthv locality, and 



* The first milk-laboratory for the exact modification of milk was 
opened in Boston in 1891 under the name of the Walker-Gordon 
Laboratory. 



144 THE ARTIFICIAL FEEDING OF INFANTS. 

every aseptic precaution taken to avoid the presence or develop- 
ment of pathogenic germs. The milk-rooms where the milk is 
received from the farm should be cool, free from dust, and iso- 
lated as far as possible from the other parts of the labora- 
tory. There should also be an entirely separate room in 
which the boxes and bottles returned by the consumer can 
immediately be sterilized in an apparatus reserved for this 
purpose. 

The modifying materials used in the laboratory should be 
carefully kept in glass vessels, at a temperature of about 4.4° C. 
(40° F.), in order to prevent the growth of bacteria. This 
is preferable to using materials in which the bacteria have 
been destroyed by heat. Separate rooms should be provided 
for the separation of milk and for its modification, and the 
office of the laboratory must also be apart from the working- 
rooms. It is also necessary that all odors be carefully excluded 
from the milk-rooms, as they are so easily absorbed by milk. 
Finally, the employees must be of sufficient intelligence to take 
a proper amount of interest in their work. 

As a result of the special care observed in the selection and 
feeding of the cattle on the Walker- Gordon farms, Laboratory 
Milk may be said to have an almost uniform percentage of its 
own at all times of the year. 

The first step towards its modification is to separate it 
into cream and skim milk. The separating-room has an as- 
phalt floor and walls of white tile, which are kept mois- 
tened and free from every kind of dirt and dust. The air 
is kept constantly pure by a ventilator. The centrifugal sepa- 
rator removes practically all of the fat from the milk except 
a small fraction (0.13 per cent.). It accomplishes two very 
important results: first, it separates from the cream and milk 
any dirt or foreign matter present, and secondly, the resulting 
cream has an almost stable percentage of fat (sixteen per 
cent. ) . The distilling apparatus is also kept in the separating- 
room. 



MODERN xMETHODS OF INFANT FEEDING. 145 

In Laboratory Milk the percentage of fat, proteids, sugar, 
and salts is not apt to vary appreciably, but the percentage 
of fat in the milk of individual cows differs from day to day 
and thus slightly affects the amount of fat present in the 
milk of the herd. To determine the fat percentage we use 
the Babcock milk-tester. In this apparatus the fat of the 
milk, previously acidulated, is completely separated by cen- 
trifugation at a high temperature. This gives the daily 
percentage of fat in the whole milk, as the sample has been 
taken from the mixed milk of the entire herd. Since the 
exact percentages of the constituents in the cream and sepa- 
rated milk are determined each day, it is easy to calculate 
the proportions of each which are required to fill a given for- 
mula. 

A physician can write for an exact prescription containing 
so much proteids, sugar, fat, and salts, and be as sure of 
obtaining it as he is of any medical formula which is filled 
at a pharmacy. These prescriptions are filled by "modify- 
ing clerks/' each of whom has at hand jars, with tightly 
fitting covers, containing the necessary ingredients, — namely, 
cream, separated milk, a carefully prepared twenty per cent- 
lactose solution, freshly made lime-water, and for older infants 
preparations of oats, barley, and wheat. The feeding-tubes 
ot bottles, the exact size and number of which are specified in 
the prescription, are filled by the clerks according to the re- 
quired formula, stoppered with sterile non-absorbent cotton, 
placed in racks or baskets designed to hold the number that is 
needed, and are then ready to be sterilized. The rule of 
absolute cleanliness is carried out in every possible detail, 
from the table on which the materials are combined to the 
dress and hands of the clerks. 

The sterilizer, which is placed in the separating-room, is so 
arranged that the steam which passes through it can be regu- 
lated so as to produce any degree of heat required up to 
100° C. (212° F.). After the food has been sterilized (as 

10 



146 THE ARTIFICIAL FEEDING OF INFANTS. 

a rule, from twenty to thirty minutes) the baskets are placed 
in a cooling tank, where the temperature of the food is reduced 
to 13.3° C. (38° F.). They are then quickly delivered to the 
consumers. 

The baskets and bottles, when returned, are taken directly 
to the wash-room, which is entirely shut off from the rest of 
the laboratory, as before mentioned. Here they are thoroughly 
sterilized and washed; the tags and stoppers are destroyed. 

The prescription blank which is used at the Walker- Gordon 
Laboratory, to be filled out by the physician, is arranged as 
follows : 

IX Per cent. 

Fat Keaction 

Milk-sugar Number of feedings 

Proteids Amount at each feeding. . . . 

Mineral matter .... Heated for 

Lime-water Heated at 

Special directions. Remarks. 

For whom ordered. Infant's age 



Infant's weisrht 



Signature. 
Date. M.D. 

It will be seen that the above blank allows the physician 
to prescribe exactly as he sees fit and to regulate the degree 
of heat employed in the preparation of the milk. The per- 
centage of mineral matter requires, as a rule, no modification 
other than that produced by the dilution. If a slightly alka- 
line reaction be desired, the amount of lime-water can be left 
to the discretion of the modifying clerk without distinctly 
specifying it. 

The prescriptions, when received, are copied into a book 
in the office of the laboratory, and are then translated into 
such a form as can readily be understood by the modifying 
clerk. 



MODERN METHODS OF INFANT FEEDING. 147 

The following table shows the practical limits of milk-modi- 
fication which can be accomplished at the laboratory. 

I. Low Fats. 

Per cent. Per cent. Per cent. Per cent. 

Fat 0.03 0.04 0.08 0.12-0.16 

Sugar 2.00 3.00 4.00-5.00 6.00-7.00 

Proteids 0.75 1.00 2.00 3.00-4.00 

II. Loav Sugars. 

Per cent. Per cent. Per cent. Per cent. 

Sugar 0.87 1.40 2.12 3.50-4.30 

Fat 2.00 3.00 3.50 4.00 

Proteids 0.75 1.00 2.00 3.00-4.00 

III. Low Proteids. 

Per cent. Per cent. Per cent. Per cent. 

Proteids 0.22 0.34 0.45 0.53 

Fat 2.00 3.00 4.00 4.50 

Sugar 2.00 3.00 4.00-5.00 6.00-7.00 

Home Modification. 

When it is impossible to obtain Laboratory Milk, Eotch 
advocates the following method of home modification, pre- 
supposing an ordinary degree of intelligence on the part of 
the mother. 

The necessary implements are as follows : 

(a) A sterilizer, which is simply a tin can large enough 
to contain the required number of nursing-bottles. It can 
be heated on the stove or, if elevated on legs, by an alcohol 
lamp. The top is perforated for the introduction of a ther- 
mometer, so that the exact temperature of its contents can be 
ascertained at any time. The tubes in which the milk is 
sterilized are simply the ordinary oblong graduated feeding- 
bottles, so constructed as to possess no corners, the bottom 
being rounded, not flat. These are stoppered with non-absorb- 
ent cotton. 

(b) A metal rack for holding the bottles, which can be 



148 THE ARTIFICIAL FEEDING OF INFANTS. 

lowered into the sterilizer; the latter is then filled with water 
to the level of the milk in the tubes. 

(c) A thick "cozy" is also to be provided, as well as (d) 
a glass graduate holding two hundred and fifty cubic centi- 
metres (eight and one-third ounces) and (e) a sugar measure 
holding 13.5 grammes (three and three-eighths drachms) of 
lactose. Finally, there must be (f) a glass siphon or tube 
bent into the shape of the letter U, for the removal of the 
milk from the jar without disturbing the cream. 

The mother should be made to understand the importance 
of obtaining a milk of good quality from a reliable dealer. 

As soon as the milk is delivered, the jar should be placed in 
ice-water (to which a teaspoonful of salt should be added for 
each quart of water) and left for six hours, care being taken 
not to allow the temperature of the water to fall below 35° F. 
At the end of this time the lower twenty-four ounces of the 
milk in the jar is siphoned off. The remaining eight ounces 
of cream will contain about ten per cent, of fat. With the 
cream, milk, milk-sugar, a fresh solution of lime-water, and 
some plain boiled water various modifications can be made, 
for which Eotch gives a number of tables. If the actual 
percentages of the fat and proteid constituents of the milk 
and cream be known, they can be combined according to some 
of the formulas devised by Westcott, Baner, and others (see 
Chapter XIII. ). 

When the mixture is completed, the feeding-bottles are filled 
with the amount to be used at each feeding, placed in the 
rack, and lowered into the sterilizer, which is filled with water 
to the level of the milk in the bottles. The temperature can 
then be raised to any desired point short of 213° F. (Eotch 
employs 171° F.), after which the can is moved to the side 
of the stove and covered with the "cozy," which in a warm 
place should retain the heat, keeping the temperature between 
167° and 170° F. for half an hour. The milk should then 
be placed in the ice-chest until used. If we wish to avoid 



MODERN METHODS OF INFANT FEEDING. 149 

coagulating the lactalbumin, the temperature must not exceed 
155° F. ; this will kill most of the bacteria in milk. If the 
milk is to be carried long distances, fractional sterilization 
may be employed to destroy the spores of the bacteria. 

Eegarding the question whether the fat emulsion of milk 
which is used for modification is interfered with or destroyed 
by centrifugation, Eotch has found by microscopic examination 
that the emulsion of one of his mixtures corresponds almost 
exactly with that of the human milk which it was made to 
represent. So far as the emulsion is concerned, no injury is 
done by separating the elements of milk and then recombining 
them. 

For a healthy infant born at term, of normal weight and 
development, Eotch regulates the quantity of food and time 
of feeding according to the table (page 142). During the 
first twenty-four to thirty-six hours he gives only small quan- 
tities of a five per cent, solution of lactose. During the first 
week he gives a mixture containing: fat two per cent., sugar 
five per cent., proteids from 0.25 to 0.75 per cent. This must 
have a slightly alkaline reaction and must be pasteurized at 
75° C. (167° F.). 



Fat. 
Per cent. 

Second week 2.5 

Third week 3.00 

"Four to six weeks 3. 50 

Six to eight weeks 3. 50 

Two to four months 4.00 

Four to eight months 4.00 

Eight to nine months 4.00 

Nine to ten months 4.00 

Ten to ten and a half months 4.00 

Ten and a half to eleven months 4.00 

Eleven to eleven and a half months Unmoc 



Sugar. 


Proteids 


J er cent. 


Per cent 


6.00 


1.00 


6.00 


1.00 


6.50 


1.00 


6.50 


1.50 


7.00 


1.50 


7.00 


2.00 


7.00 


2.50 


7.00 


3.00 


5.00 


3.25 


4.50 


3.50 


ed cow 


s milk 



150 THE ARTIFICIAL FEEDING OF INFANTS. 

At about the tenth or eleventh month Botch usually begins 
to give one and then two meals daily of oat jelly and plain 
milk, pasteurized at 68° C, equal parts, with a pinch of 
salt added to suit the infant's taste. Barley or wheat may 
also be used. In the twelfth month he accustoms the infant 
tq taking bread (one day old) and to eat with a spoon, so 
that at one year of age it takes bread and milk for breakfast 
and supper and oat jelly and milk for the three middle meals. 

W. P. Northrup 221 dwells on the importance of " clean" 
milk which is moderately free not only from bacterial con- 
tamination, but also from the products of their activities, — 
the toxins. The formation of the latter can be prevented by 
the immediate cooling of the milk, after it is drawn, to 40° F., 
at which temperature most bacteria cannot grow. 

In Northrup's experience with centrifugal cream, "there 
has never arisen any accident or incident to raise objection to 
it." Moreover, its all-important freshness is an argument in 
its favor which it is difficult to overturn. He would limit the 
use of home modifications to those infants who are already well 
started and thriving and to those who are not to be consid- 
ered as delicate or in a critical state. " For really difficult 
cases (critical cases), in which there is risk in trying things, 
in which it is necessary to find the right feeding at once, and 
in which the condition of the child is such that it is impor- 
tant not to risk any time, he has no hesitancy in saying that 
there is no feeding so reliable and so good as the modified 
milk." The only objection to the use of Laboratory Milk is 
its expense. 

Northrup also insists that the physician should have a proper 
knowledge of what the infant requires at different periods of 
its life before he attempts to prescribe this or that formula. 

The three most important formulas to remember are: (1) 
Feeding for the new-born (proper for the majority) : fat 
two per cent., sugar five per cent., proteids 0.75 per cent. 
(2) "Low average breast-milk:" fat three per cent., sugar 



MODERN METHODS OF INFANT FEEDING. 151 

six per cent., proteids one per cent. ( 3 ) " High average 
breast-milk:' 7 fat four per cent., sugar seven per cent., pro- 
teids two per cent. These modifications should be changed 
gradually and frequently, by small fractions, from one to 
another. From eight months to one year the proportions should 
be made to approximate cow's milk. The diet should be all 
milk for the first year and mostly milk for the second year. 

Koplik T9 divides the cases under his observation in his 
dispensary service in New York City into two classes: (a) 
those who were fed from birth on modified cow's milk, and 
(b ) those who were given the breast in addition to cow's milk. 
All were under nine months of age. The milk was sterilized 
at from 90° to 92° C. and rapidly cooled. The same mixture 
was given to all cases. It was composed of equal parts of 
cow's milk and distilled water, with six per cent, of crystal- 
lized milk-sugar, — the so-called Heubner-Hoffmann Mixture. 
Children under three months received ninety cubic centi- 
metres; older children were given one ounce (thirty cubic 
centimetres) more for each month of their age till eight ounces 
(two hundred and forty cubic centimetres) were reached, when 
whole milk was used. Each child was given from seven to 
eight bottles a day. The mothers were told not to give more 
than one and a half ounces at a time to babies under one 
month. Systematic weighings were carried out. 

The Heubner-Hoffmann Mixture contains: water 90.57 per 
cent., proteids 1.78 per cent., fat 1.85 per cent., sugar 5.44 
per cent., and ash 0.36 per cent. 

During the last five years this mixture proved satisfactory 
in the majority of cases. In a few cases the deficiency in 
fat was made up as follows : sixteen per cent, cream was added 
to each one hundred parts of the Heubner-Hoffmann Mixture, 
so as to make the fat content four per cent. We know that 
relatively larger quantities of cow's milk than of human milk 
are required for the healthy nutrition of infants; but there 
is no excessive consumption, even when quantities are taken 



152 THE ARTIFICIAL FEEDING OF INFANTS. 

which are greater than the known capacity of the stomach 
(see Camerer^s monograph, Vienna, 1898). The best results 
in feeding sickly infants were obtained with Biedert's minimal 
amounts. 

Class A. — In thirty cases Koplik found an increase in 
weight: from first to second month, thirty-two grammes; 
second to third month, 17.4 grammes; third to fourth month, 
23.6 grammes; fourth to fifth month, eighteen grammes; 
fifth to sixth month, 14.2 grammes; sixth to seventh month, 
11.8 grammes; seventh to eighth month, 15.6 grammes; eighth 
to ninth month, 15.1 grammes. These were all dispensary 
cases from the lowest classes, whose hygienic surroundings were 
most unfavorable, and where the increase in weight was liable 
to be interfered with by frequent attacks of diarrhoea and other 
diseases. 

Class B. — Infants who are given the breast in addition to 
the bottle undoubtedly have less tendency to diarrhoea and 
digestive disturbances. The average weight and the daily 
increase in weight are greater by far than in those cases 
which are fed on the bottle alone. The daily gain was greatest 
from the eighth to the twelfth and the twelfth to the six- 
teenth week, at a period when artificially fed children have 
the greatest difficulty in maintaining their weight. If we take 
thirteen cases in which the babies were given the breast and 
the bottle alternately, we note the following gain in weight: 



5-12 


12-16 


16-20 


20-24 


24-28 


28-32 


32-36 week 


30 


24.8 


12 


19.5 


13.7 


9.2 


11.2 per cent. 



Koplik ascribes the irregularity in the gain to the tendency 
of mothers to overfeed their children, thus leading to dys- 
pepsia and temporary losses. Nevertheless, the gain compared 
favorably with that given by Camerer in his table estimated 
from weighings of fifty-nine breast-fed infants. 

Biedert, Meigs, and Eotch have devised methods by which 
we can imitate the natural food of the infant. Of these the 



MODERN METHODS OF INFANT FEEDING. 153 

Meigs Mixture is unquestionably the best milk-modification 
that we have at present. It is a mistake to think that all we 
have to do is to recombine the elements of milk in the pro- 
portions present in mother's milk. Even with the method 
of Rotch, which allows all possible variations of the proteids, 
fat, and sugar percentages, there are a certain number of 
infants who will not thrive on any mixture we can devise. 
These are the cases in which atrophy gradually develops, 
and include those children who cannot digest milk in any 
form. 

While some atrophic infants do not thrive on a fat per- 
centage similar to that of mother's milk, in others the pres- 
ence of the fat seems to favor digestion of the casein. This 
simply serves to show how complicated the problem of infant 
feeding really is. When we consider that in our great cities 
the majority of mothers have to depend on some form of home 
modification, the best of which are those formulated ' by Bie- 
dert, Meigs, and Heubner, we see that it is not so much the 
difference between 1.2 and one and a half or two per cent, 
proteids which decides the child's destiny as something in- 
herent in the milk itself, in that we have to do with casein 
which is very indigestible, especially in the raw state. 

Joseph C. Winters. 235 An artificial food must contain 
nothing that is not found in human milk ; it must be of animal 
origin and it must be fresh. In metropolitan cities, where 
the milk reaches the consumer sixteen hours or more after 
milking, the proportions of the ingredients in the top milk 
will be fairly constant. Analyses made by Adriance of good 
milk as delivered in New York City show that the upper 
ounce from a quart of it will contain: fat 23.8 per cent., 
sugar 3.90 per cent., proteids 2.90 per cent.; the upper four 
ounces will contain: fat 21.8 per cent., sugar four per cent., 
proteids three per cent. ; and the upper eight ounces will 
contain: fat seventeen per cent., sugar 4.3 per cent., proteids 
3.1 per cent. Winters advises for the early days of infancy 



154 THE ARTIFICIAL FEEDING OF INFANTS. 

no more than 0.25 per cent, proteids and no less than two 
per cent. fat. Infants so fed do not lose weight in the first 
week of life as they do under other conditions. An infant 
from three to four months old will not, as a rule, digest more 
than one per cent, of proteids in hot weather. At this time 
the proportion of lime-water should be increased to one-fourth 
of the total quantity used, and the strength of the food should 
be increased very gradually. Winters has seen scurvy follow 
the use of pasteurized milk, with rapid recovery on the use of 
the same food raw. He prefers, whenever possible, to employ 
milk which has not been heated. 

Thompson S. Westcott. 254 This author believes with Eotch 
that milk-modifications should be prescribed in formulae ex- 
pressing the percentage composition of the different ingredients. 
For this purpose whole milk and creams of varying strengths 
are combined according to mathematical formulae. He also 
gives a table showing the varying percentages of fat and pro- 
teids that can be obtained by mixing whey with cream of 
various fat percentages. In these estimations the amount of 
proteids is calculated according to Konig's analyses, which give 
2.88 per cent, casein and 0.53 per cent, lactalbumin in cow's 
milk; the whey-proteids are estimated to equal 0.86 per cent. 
(see Chapter XIII.) . 

Westcott emphasizes the importance of maintaining the di- 
gestive equilibrium. For this purpose clinical experience has 
taught him that liberal amounts of milk and cream are needed. 
In mixtures containing from thirty to thirty-two ounces, for 
instance, the quantity of milk and cream must reach from 
twelve to thirteen ounces before satisfactory growth and nutri- 
tion can be expected. Dilutions weaker than this must be 
considered underfeeding. Both upon theoretical and clinical 
grounds, a percentage of proteids below 1.50 must be con- 
sidered subnormal for any but the youngest infants; there- 
fore, when low feeding must be maintained for a considerable 
time, this percentage should be kept constantly in mind as 



MODERN METHODS OF INFANT FEEDING. 155 

the index of concentration which it is desirable to reach as 
soon as the strength of the infantas digestion will permit. 

Westcott advises as a good working mle to make the fat 
percentage abont three when the proteid percentage is one, and 
gradually to increase it to four, while the proteid percentage 
is increased to two. Exceptionally the fat percentage must 
be reduced below three for delicate infants or those of very 
tender age. For the purposes of modification : 

Fat. Proteids. Sugar. Salts. 

Per cent. Per cent. Per cent. Per cent. 

Whole milk is calculated to consist of .. . 4.00 4.00 4.40 0.70 
Twelve per cent, cream is calculated to 

consist of 12.00 3.80 4.20 0.64 

Sixteen per cent, cream is calculated to 

consist of 16.00 3.60 4.00 0.60 

Twenty per cent, cream is calculated to 

consist of 20.00 3.20 3.80 0.55 



When it is necessary to reduce the proteids below one per 
cent, to establish digestive equilibrium, the use of the whey- 
proteids will enable the infant to appropriate a larger propor- 
tion of the more assimilable soluble albuminoids and perhaps 
a higher percentage of total proteids than any other plan of 
feeding. For this purpose, in preparing the whey, the curd, 
after forming, should be disturbed as little as possible, the 
whey being allowed to drain off entirely by gravity. The 
object of this is to obtain as low a percentage of fat as pos- 
sible, since the mixture will now become essentially a cream 
dilution and nearly all the fat will be derived from the cream. 

In a general way it may be said that in normal cases a pro- 
teid percentage of two should not be reached before the fifth 
or sixth month. In infants with chronic digestive disturbances 
it may be several months later before so high a percentage 
can be attained, and in cases of delicate digestion it may not 



J 56 THE ARTIFICIAL FEEDING OF INFANTS. 

be possible to increase the percentage above two until near the 
end of the first year. 

Since human milk contains from 6.5 to seven per cent, lac- 
tose, a corresponding percentage of sugar may be given in 
the mixture, except in the earliest days of life, when a per- 
centage of 4.5, five, or 5.5 would be more suitable. Crystalline 
milk-sugar is to be preferred to the ordinary powdered sugar, 
which can readily be adulterated. It is preferable to add the 
necessary weight of sugar in dry form rather than to use a 
watery solution of definite percentage strength. 

In cases of weak gastric or intestinal digestion in which 
only very low percentages of proteids can be assimilated, de- 
cided advantage is often gained by partial predigestion of the 
milk mixture. In this way, too, higher percentages of proteids 
can be given than is possible with simple dilutions. The author 
prefers to use peptogenic milk-powder for this purpose. Since 
this consists largely of milk-sugar, the bulk of the powder must 
be deducted from the quantity of milk-sugar added to bring 
the mixture to the desired percentage. The author has never 
observed the often-described ill effects of a partially peptonized 
diet, although this mode of preparation has been employed in 
many cases that demanded it for from three to six months or 
even longer. 

It is usually best to discontinue partial predigestion slowly, 
first gradually reducing the time of action to three or four 
minutes, and then decreasing the quantity of powder to a third 
or fourth of the amount originally used, after which it may 
be omitted. 

For clinical purposes Woodward's method of estimating the 
proteids in breast-milk and the Leffmann-Beam method for 
the estimation of fat are recommended (see Appendix). 

Fraxklix W. White and Maynard Ladd 203 have recently 
called the attention of the profession to the subject of whey- 
cream modifications in infant feeding. They found, on re- 
ferring to Bulletin 28 of the United States Department of 



MODERN METHODS OF INFANT FEEDING. 157 

Agriculture, that a large number of specimens of whey, as 
purchased, yielded one per cent, of whey-proteids. Konig's 
analysis of whey, accepted by Westcott, allowed 0.86 per cent, 
for whey-proteids, and Westcott's formulae were based on this 
figure. The result of six analyses by the authors confirmed 
the presence of one per cent, of proteids in whey. Several 
analyses of the total proteids in whole cow's milk gave 3.84 
per cent.; of this, the average amount of whey-proteids was 
0.90 per cent., or approximately one-quarter of the total pro- 
teids; the average amount of caseinogen was 2.94 per cent., 
or approximately three-quarters of the total proteids. They 
found that the best temperature for destroying the rennet 
enzyme in whey was 65° C. (149° F.). Temperatures of 
69.3° C. and higher coagulate the whey-proteids. The rennet 
must be destroyed before mixing the whey with the cream, 
in order to prevent the coagulation of the cream by the enzyme. 

By the use of thirty-two per cent, cream, fat-free milk, and 
a very concentrated solution of milk-sugar they were able to 
obtain whey-cream mixtures with a maximum of 0.90 per 
cent, of whey-proteids in combination with percentages of 
caseinogen varying from 0.25 to one, giving total proteids of 
from 1.15 to 1.90 per cent. 

The emulsions of fat in whey, barley-water, gravity cream, 
and centrifugal cream mixtures were the same both in their 
macroscopic and microscopic appearances. The combination 
of heat and jolting during transportation, such as sometimes 
occurs in hot weather, partially destroys the emulsion in all 
forms of modified milk, but this disturbance can be prevented 
by the simple precaution of keeping the milk cool during de- 
livery. 

Whey-cream mixtures yield a much finer, less bulky, and 
more digestible coagulum than plain modified mixtures with 
the same total proteids; the coagulum is equalled in fineness 
only by that of barley mixtures. The coagulum yielded by 
gravity cream mixtures and centrifugal cream mixtures is the 



158 THE ARTIFICIAL FEEDING OF INFANTS. 

same in character. The density of the coagulum is not affected 
by a variation of five per cent, in the fat content of the cream. 
Experiments on animals confirmed the results obtained in the 
test-tubes. 

Chakles W. Townsend 145 emphasizes these practical points 
in infant feeding: that the child is not a machine, that chil- 
dren vary greatly in their digestive powers, and that they will 
not always do what is expected of them. Even with the most 
patient and intelligent changing of the formulas to suit the 
varying needs of the case, laboratory modifications will not 
always agree, " though often of the greatest service." He 
thinks that a possible explanation lies in the fact that the 
cream separated by centrifugation recombines with milk, 
water, and lactose in varying proportions, and is then churned 
up by being carted around on the delivery wagon (see May- 
nard Ladd and White). He does not insist on pasteurization 
if the milk be : ( 1 ) fresh, ( 2 ) obtained from cows which are 
found to be free from tuberculosis by the tuberculin test, and 
(3) in no danger of contamination by the germs of typhoid 
fever or other infectious diseases. If there is doubt as to these 
three particulars, it is better to pasteurize at 156° F. for 
twenty minutes. 

For home modification he recommends the use of top milk 
(upper fourth) which contains four per cent, proteids and 
from ten to eleven per cent, fat after standing from six to 
eight hours. His rule is : each ounce of ten per cent, cream 
in a twenty-ounce mixture represents .50 per cent, fat, .20 
per cent, proteids, and .20 per cent, sugar. Each even table- 
spoonful of sugar of milk represents two per cent. The dilu- 
tions are made with lime-water and boiled water. Skimmed 
milk may be employed when it is desirable to increase the 
percentage of proteids. When using mixtures low in proteids, 
as in entero-colitis, the addition of white of egg is useful. 

H. Dwight Chapin 25 > 201 has recently recalled the atten- 
tion of the profession to the use of top-milk mixtures in 



MODERN METHODS OF INFANT FEEDING. 159 

infant feeding, and this subject will be discussed in Chap- 
ter XIII. He is also a prominent advocate of the use of 
decoctions of the cereals in infant feeding. 247 " The claim 
that cereal waters have no more effect on the curd of cow's 
milk than plain water has been abandoned, as it was based 
on the precipitation of casein with dilute acids and not upon 
its coagulation with rennet, which is what takes place in the 
infant's stomach. ... To break up the curd of cow's milk 
and furnish a small quantity of easily absorbable food, cereal 
gruels, in which the starch has been converted into dextrin 
and maltose, are the most practicable and desirable agents. 
It is now admitted that cereals give the finest curd of any 
diluent, but it is claimed that the effect of the cereal is lost 
when the starch is digested, especially if the digestive ferment 
is active. How much effect a digested gruel has on the curd- 
ling of milk depends on the strength of the gruel and the dilu- 
tion of the milk. The very best effect, so far as the digestive 
effort is concerned, is obtained when the starch is completely 
gotten into soluble forms, so that the particles of proteids 
and cellulose of the cereals are free." Experiments were made 
by adding rennet and 0.15 per cent, hydrochloric acid to 
(a) raw milk diluted equally with water, (b) the same diluted 
equally with one and a half per cent, starch jelly, and (c) 
the same diluted equally with dextrinized gruel. In b and 
c the curds were smaller and more flocculent than in a; in b 
the curds were coated with starch, but in c they were thor- 
oughly exposed to the action of the gastric juice. 

" It is not necessary to use a gruel stronger than one heap- 
ing tablespoonful of flour to the pint for any dilution of milk. 
Wheat, oatmeal, or barley may be used. Besides acting as 
mechanical attenuants, gruels possess some nutritive value, 
since they contain dextrin and maltose, which are readily 
absorbed." 

A simple decoction of diastase may be made at home as 
follows. A tablespoonful of malted barley grains is put in 



160 THE ARTIFICIAL FEEDING OF INFANTS. 

a cup and enough cold water added to cover it. This should 
be prepared in the evening and placed in the refrigerator over- 
night. In the morning the water is strained off and is ready 
for use. The diastases on the market or most of the thick 
malt extracts may also be employed. " Cereo," an active glyce- 
rite of diastase, is now especially made for dextrinizing gruels. 
In cases in which the infant cannot take milk of any kind, 
Chapin has found the following to be of great use: 

I. Dextrinized wheat gruel, eight ounces ; 
White of one egg (large) ; 
Two even teaspoonfuls of granulated sugar. 

This combination gives about two per cent, proteids and seven 
per cent, soluble carbohydrates. 

II. Dextrinized wheat gruel, eight ounces ; 
Yolk of one egg (large) ; 
Two even teaspoonfuls of granulated sugar. 

This mixture will yield about 1.7 per cent, fat, 1.7 per cent, 
proteids, and seven per cent, soluble carbohydrates. The yolk 
also contains phosphorus and iron in organic combination. 

Leeds 133 expresses the following views with regard to the 
use of dextrinized attenuants. A gummy material like dextrin 
or a finely divided starch like that in oatmeal- or barley-water, 
along with more or less glutinous extractive matter, is much 
better adapted to serve as a mechanical attenuant of casein 
than farinaceous foods in their ordinary condition. 

Floyd M. Craistdall 239 believes that the secret whereby 
the specialist may succeed in finding the proper proportions 
for an infant's diet more quickly than the practitioner of small 
experience is an open one, — namely, to begin on a weak mix- 
ture and work up to a point of tolerance. The average prac- 
titioner is afraid to dilute the milk sufficiently at the outset, 
and does precisely the opposite. 

The three principal items to remember when writing for- 



MODERN METHODS OF INFANT FEEDING. 161 

mulae at the bedside are these: nine ounces of top milk 
contain twelve per cent, fat and four per cent, proteids; 
eleven ounces of top milk contain ten per cent, fat and four 
per cent, proteids; fifteen ounces of top milk contain eight 
per cent, fat and four per cent, proteids. The fact that one 
part of sugar to twenty parts of mixture will give a percentage 
of five is obvious. 

By the simplest of calculations a great variety of formulae 
can be arranged. The one source of error lies in the varying 
strengths of different milks, but this objection applies to every 
method of home modification. 

Louis Fischer 171 calls attention to the fact that the natu- 
ral food of an infant is neither boiled, sterilized, nor pasteur- 
ized, and believes that with the improved hygiene of the dairy 
it is safer to administer raw milk and thus avoid any risk of 
the development of scurvy. He agrees with the views expressed 
by Jacobi regarding the employment of modified Laboratory 
Milk. In his own experience, children fed on it were back- 
ward in development for a long time after its use. They 
always looked anaemic and their flesh was flabby, although 
their hygienic surroundings were of the best. He thinks that 
once the emulsion is destroyed by centrifugation or other 
mechanical process it cannot again become as homogeneous as 
before. 

Ashby and Wright 2 recommend that milk should be pre- 
pared in the following manner. A thirty-ounce bottle is filled 
with fresh milk, plugged with cotton, and placed in an ice- 
chest or as cool a place as possible for five hours. The lower 
half is siphoned off and replaced with an equal quantity of 
seven per cent, lactose solution. This is sterilized at 160° F. 
for thirty minutes, cooled rapidly, and kept at a low tempera- 
ture. The quantity to be given at each feeding must be heated 
to 100° F. before administering. With good milk this mixture 
will contain on the average 1.8 per cent, proteids, from three 
to three and a half per cent, fat, and six per cent, sugar. 

11 



162 THE ARTIFICIAL FEEDING OF INFANTS. 

For very young or delicate infants a weaker mixture may be 
made by siphoning off the lower two-thirds of the milk and 
adding five per cent, sugar solution. It is always well to 
render it alkaline by the addition of a few grains of sodium 
bicarbonate or a small quantity of a saturated solution of 
lime. We must not forget that milk is richer in winter, when 
the cows are stall-fed, than in spring, when they are at pas- 
ture. By increasing or diminishing the time of standing (five 
hours) we can increase or diminish the proportion of fat. 
For the poorer classes milk diluted only with lime-water or 
plain water must be used. At first two-thirds of the total 
quantity should consist of five per cent, sugar solution and 
one-twentieth lime-water. For a new-born baby it is un- 
doubtedly best to begin with whey or diluted peptonized milk. 
After the first three or four weeks, if the digestion is good, 
equal parts of milk and sugar-water and one-tenth lime-water 
may be used. From three to six months give two-thirds milk 
and one-third sugar-water. 

Whey may be given either alone, diluted with barley-water, 
or as a diluent for milk or cream. It is undoubtedly true that 
very many children are brought up on diluted cow's milk 
without cream and apparently thrive on it. Many such pass 
much curd in their stools without being the worse for it. The 
amount of food to be given depends partly on the age, partly 
on the powers of digestion of the infant and the degree of 
its development. It is as important to regulate the times 
for feeding and the amount as it is to decide on the nature 
of the food; neither age nor weight should be taken blindly 
as a guide to the amount of food that the infant should 
take. 

At one month (weight from six to eight pounds) give from 
one to two ounces every two and a half hours. Eight bottles 
are required, with a total content of from twelve to fifteen 
ounces. 

At two months (weight from eight to eleven pounds) give 



MODERN METHODS OF INFANT FEEDING. 163 

from three to four ounces every two and a half hours. Eight 
bottles are needed, containing from twenty to thirty ounces 
in all. 

From three to four months (weight from eleven to four- 
teen pounds) give from four to five ounces every three hours. 
Seven bottles are needed, containing from thirty to thirty-five 
ounces in all. 

For the fifth and sixth months (weight from fourteen to 
sixteen pounds) give from six to seven ounces every three 
hours. Six bottles are needed, and the total quantity is from 
thirty-five to forty ounces. 

Ashby believes that the addition of thin starchy fluids, such 
as barley- and oatmeal-water, after the third or fourth month 
checks rapid curdling of the milk and is of considerable value 
for the infant's nutrition. In some cases milk so diluted is 
better assimilated than when plain water is used. Under 
three to four months starch should be dextrinized. 

Barley jelly, whole meal, maize, or oatmeal may be added 
to the diet at six or seven months, provided they are not in 
too concentrated solution to pass through the nipple. At 
seven months the child may have a crust to nibble on, but no 
other solid food, such as eggs. 

Cautley 38 advises the following dilutions during the early 
months of life. The figures represent teaspoonfuls. Lime- 
water is to be added after boiling; if cream cannot be ob- 
tained, take an extra teaspoonful of top milk : 



First week. Second week. Third week. Fourth week. 

Milk 2 3 4 5 

Cream 1 1 1 1 

Water 5 6 7 8 

Lime-water 1 1 1 1 

One lump of sugar is to be added to each feeding. 



164 



THE ARTIFICIAL FEEDING OF INFANTS. 



Third to sixth 
month. 



Sixth to ninth 
month. 



Two months. 

Boiled cow's milk. 2 tablespoonfuls 3-4 tablespoonfuls 5-6 tablespoonfuls 

Boiled water 2 tablespoonfuls 

Barley-water 3-4 tablespoonfuls 5-6 tablespoonfuls 

Cream 1 teaspoonful 1-4 teaspoonfuls 

Lime-water 3 teaspoonfuls 

When cream cannot be obtained, cod-liver oil may be used instead after 
the sixth month. One lump of sugar is to be added to each of the mixtures. 

Cautley believes that after the age of two months most 
infants can take milk diluted equally with water; in some cases 
it is necessary to still further dilute the milk (even seven or 
eight times), but by sufficient dilution at first any infant can 
become accustomed to take cow's milk. In his experience, 
cane-sugar can readily replace lactose without an}' ill effect, 
if given in the correct proportion. Milk-sugar ferments very 
much more readily than cane-sugar. When the milk-supply 
is adequate, starch should not be given to young infants (ex- 
cept in small quantities and in very weak solution) until the 
time of weaning. The appearance of six teeth may be con- 
sidered an indication for its administration. Barley-water 
sometimes causes starchy indigestion. Stale bread, biscuit, 
crackers, and corn flour may be used towards the end of the 
first year. 

Dextrinized attenuants act mechanically. Oatmeal contains 
more starch than barley-water and wheat more than either. 
The latter is therefore less easily acted on by the saliva. 

Fenwick 52 advises the following mixtures for routine use 
during the first year of the infant's life. 

First week: 



Cream 2 teaspoonfuls 

"Whey 3 teaspoonfuls 

Lactose 10 grains 

Water . . . . ; 3 teaspoonfuls J 



Cow's milk . 
Barlev-water 



1 tablespoonful 
1 tablespoonful 



MODERN METHODS OF INFANT FEEDING. 



165 



From the second to the fourth week give each second hour 
from four a.m. to ten p.m. : 



Cream 2 teaspoon fuls 

Cow's milk 1 tablespoonful 

Lactose 15 grains 

Water 1 ounce 



Cow's milk .... 6 teaspoonfuls 
Barley-water ... 5 teaspoonfuls 
Lactose 15 grains 



For the third month give each two and a half hours from 
five a.m. to eleven p.m. : 



Cream 3 teaspoonfuls 

Cow's milk ... .12 teaspoonfuls 

Lactose 28 grains 

Water 1 ounce 



' Cream 3 teaspoonfuls 

Cow's milk ... .12 teaspoonfuls 
Lactose 30 grains 

„ Barley-water . . .12 teaspoonfuls , 



For the fourth month give each two and a half hours from 
five a.m. to eleven p.m. : 



Cream 3| teaspoonfuls 

Cow's milk ... .12 teaspoonfuls 

Lactose 40 grains 

Water 2 ounces 



Cream 4 teaspoonfuls 

Cow's milk .... 2 ounces 

Lactose 45 grains 

. Barley- water ... 2 ounces 



For the fifth month give each three hours from five a.m. to 
eleven p.m. : 



Cream 4 teaspoonfuls 

Cow's milk .... 2 ounces 

Lactose 50 grains 

Water H ounces 



Cream 5 teaspoonfuls 

Cow's milk ... .18 teaspoonfuls 

Lactose 1 teaspoonful 

Barley-water ... 2 ounces 



For the sixth month give each three hours from five a.m. 
to eleven p.m. : 



Cream 4 teaspoonfuls 

Cow's milk ... .20 teaspoonfuls 

Lactose 1 teaspoonful 

Water 1 ounce 



Cream 5 teaspoonfuls 

Cow's milk ... .20 teaspoonfuls 

Lactose 1 teaspoonful 

Barley-water . . . 1 J ounces 



166 THE ARTIFICIAL FEEDING OF INFANTS. 

From six to twelve months the first meal should be at seven 
a.m. : one teacupful of dilute alkaline milk, humanized milk, 
or cream mixture. Second meal at 10.30 a.m. : milk as above, 
with a teaspoonful of malted food such as Mellin's Food, or 
bread jelly, or two teaspoonfuls of barley jelly. The third and 
fourth meals should be as above at two p.m. and six p.m. 
The last meal is to be given at 9.30 p.m. or ten p.m., and should 
be like the first. After seven months one teaspoonful of whole 
meal flour may be used instead of Mellin's Food, or a little 
fine oatmeal porridge may be allowed at the first meal. If 
indigestion follows or the infant ceases to gain, the food should 
be predigested with malt. After the ninth month the yolk 
of a soft-boiled egg may be given for the third meal, or a cup 
of veal, chicken, mutton, or beef broth with stale bread-crumbs. 

Fenwick advises the use of lime-water in the milk in the pro- 
portion of one to twenty, to render it alkaline, and considers 
that barley-water is preferable to plain water as a mechanical 
diluent. 

John Thomson 143 allows the healthy infant to take as 
much as it wants at regular hours of feeding. As a general 
rule, for the first six weeks of life he uses milk diluted with 
two or three times its bulk of water; from one and a half 
to four or five months, equal parts of milk and water; from 
the fifth to the eighth or ninth month, two parts of milk and 
one part of water, increasing after this until at the end of 
the year pure milk is given. In difficult cases he makes use 
of Frankland's, Meigs's, or Botch's mixtures. 

To neutralize the acidity, he recommends the use of lime- 
water in the proportion of one-sixth to one-eighth; sodium 
bicarbonate or magnesia may be used instead. The percentage 
of sugar should be brought up to normal by the addition of 
lactose or, if this is not obtainable, cane-sugar. 



CHAPTER VI. 
WEANING. 

Authorities are nearly in accord as to the proper time 
to institute weaning. If the child is thriving and showing 
satisfactory gain in weight and development, breast-milk alone 
is sufficient until the ninth to the twelfth month (Starr, 
J. Lewis Smith, Williams, Cautley, Ashby and Wright, Thom- 
son, Bendix, Monti, Gerhardt, Marfan, Taylor and Wells, Cro- 
zer Griffith, etc.). 

Comby prefers to wean late (from the fifteenth to the eigh- 
teenth or twentieth month) ; he advises that the breast and 
the bottle should be given alternately. Marfan also thinks 
that it is advisable to keep the infant at the breast until the 
sixteenth month, but not after the eighteenth month, giving 
in addition artificial food. The breast-milk may prove a great 
resource in case of illness. A good indication for the adminis- 
tration of other food than that from the breast is the cutting 
of four teeth, showing that the development of the digestive 
tract is advancing. 

On the other hand, Monti is inclined to believe that breast- 
feeding after the twelfth month is apt to result in malnutri- 
tion, anaemia, etc. Infants so fed may be fat, but will not 
necessarily be strong. Ashby expresses similar views. (These 
remarks seem to apply to infants fed solely at the breast. — 
Editors.) 

Rarely it may be necessary to wean early — at the age of 
five or six months — if anomalies in the mother's milk develop 
or if the infant is not making satisfactory progress. In the 
latter case it is well to add artificial nourishment to the diet, 
but not to wean entirely until the necessary physiological de- 
velopment has taken place." 

167 



168 THE ARTIFICIAL FEEDING OF INFANTS. 

The child should not be weaned during the hot months of 
the year, nor during or immediately after an illness, nor during 
a gastro-intestinal disturbance, unless this is due to a per- 
sistent faulty composition of the breast-milk. 

Mixed Feeding. 

Mixed feeding is preferable to insufficient nourishment from 
the breast, and is to be preferred to exclusive artificial feeding. 
The breast and bottle should be given alternately, and both 
breasts should be given at each nursing to maintain their 
secretion (Marfan). The value of mixed feeding is univer- 
sally admitted. 

Indications for Weaning. 

Monti." I. Eepeated profuse menstruation (during which 
the child loses weight on account of changes in the composition 
of the milk). 

II. Pregnancy (requires immediate weaning). 

III. Acute infectious febrile disorders (unless of very short 
duration). 

IV. Failure of the child to thrive. 

(The last indication calls for mixed feeding rather than for 
absolute weaning, unless careful analysis of the mother's milk 
shows that it is entirely unsuited to the needs of the infant. — 
Editors.) 

Opinions differ as to the effects of menstruation and preg- 
nancy on the secretion of the breasts. Marfan thinks that 
under ordinary circumstances the return of the menses does 
not necessitate weaning, unless marked digestive disturbances 
occur and the child ceases to gain for a certain length of time. 
Pregnancy is not incompatible with nursing; if the mother is 
strong and healthy, she can nurse her child until the latter 
months of gestation. The mother's condition and the amount 
of milk she secretes must decide the question (Bendix). 

Comby 62 considers that the return of the menses should 



WEANING. 169 

never demand immediate weaning. There may be some tem- 
porary disturbance, but one should not on this account wean 
prematurely. 

Bendix, 226 from the careful study of one hundred and forty 
cases, concludes that the mere occurrence of menstruation is 
insufficient ground for weaning, even when alterations take 
place in the quality and quantity of the milk, since these 
changes are of a temporary character only and will not seri- 
ously affect the child's condition. He also considers that the 
infectious fevers are not a contraindication to nursing. In 
one case of measles, one of scarlet fever, and one of influenza 
the mothers were able to nurse their babies throughout the dis- 
eases and the infants remained healthy (except for a slight 
dyspeptic attack in the latter case) . Tuberculosis is of course 
a positive contraindication to nursing. 

Taylor and Wells 147 think that, as a general rule, it is 
best to wean on the diagnosis of pregnancy being established, 
since this disturbs the equilibrium of the milk secretion. Usu- 
ally, too, the continuance of menstruation affects the compo- 
sition of the milk to a marked degree. According to Eotch, 
there is a decided increase in the proteids and a diminution 
in the fat. By emptying the breasts with a pump these periods 
may be tided over and the necessity to wean may be averted. 

Holt. 1S3 It is important that the physician should be fa- 
miliar with the symptoms of inadequate nursing. During the 
first days of life an important sign is a rise of temperature 
to 101° or 102° F., or higher, without obvious signs of ill- 
ness. 

Symptoms of inadequate nursing may be grouped as follows : 
colic, fretfulness, loss of sleep, with either no gain in weight 
or a loss of several ounces a week, and abnormal stools. All 
of these, persisting beyond the third or fourth week of the 
mother's convalescence, justify immediate weaning. 

" Since artificial feeding, when properly carried out, gives 
so much better results than poor or doubtful nursing, it is 



170 THE ARTIFICIAL FEEDING OF INFANTS. 

better to stop nursing after a fair trial — i.e., two weeks — has 
been made rather than waste time in prolonged efforts to 
improve the breast-milk." 

Method of Weaning. 

All authorities are agreed that it is advisable to wean gradu- 
ally; the time required for gradual weaning is from two to 
five weeks. For instance, Monti says to give one extra meal 
a day for one week, two a day during the next week, three a 
day during the third week, and -so on. At the end of four or 
five weeks cease nursing altogether. 

Undoubtedly the best food with which to wean a child is 
properly prepared cow's milk. The child has to learn to digest 
cow's milk casein just as in the early months of life, but with 
much greater probability of success. It is safer, therefore, to 
begin with a high dilution of cow's milk, such as one part of 
milk to two parts of water, with the addition of cream if 
desired. If this agrees, the strength of the mixture can 
rapidly be increased until at the end of two weeks equal parts 
of milk and water and at the end of one month three parts 
of milk to one of water or whole cow's milk may be given. If 
weaning is carried out before the tenth month, a longer time 
may be necessary, and for infants of weak digestion higher 
dilutions or special mixtures may be required. In preparing 
the milk mixture for weaning it will usually be found advan- 
tageous to use a starchy decoction, such as barley-water, for 
our diluent instead of plain water, or to add one of the reli- 
able infant foods. This addition of starch is indicated not 
only to render the milk more digestible, but also to increase 
the proportion of carbohydrates. Holt's rules (see page 139) 
for the feeding of difficult cases during the second year hold 
good for any case in which the digestion of cow's milk offers 
special difficulty. Again, many children do well on milk mix- 
tures, but suffer from repeated attacks of indigestion following 
the administration of solid food. Starches in concentrated 



WEANING. 171 

form, such as cakes, bread, potatoes, oatmeal, etc., will gen- 
erally be found to be the articles at fault; their withdrawal 
and the substitution of milk and broths will usually be fol- 
lowed by complete recovery. The common practice of giving 
the infant a " taste" of tea, coffee, or alcoholic beverages need 
only be mentioned to be condemned. Under the following 
headings we have included those articles of food which may 
form the child's diet from the time of weaning until the end 
of the second year. Experience has shown that infants do best 
on plain food. Once the child has acquired a taste for sweets 
and highly seasoned articles of food it will rarely be satisfied 
without them; therefore it is much kinder to withhold such 
articles absolutely until a later period of life. 

Starches. 
After the ninth month starches may be given to healthy 
infants, and sometimes earlier, provided five or six incisors 
have appeared and there is an abundance of saliva present. 
The best preparations of starch are thoroughly cooked gruels 
or jellies and the infant foods, preferably those which are 
dextrinized or malted; ""Infant's Zwieback" may also be 
recommended. If one of the infant foods is selected, begin 
by adding one teaspoonful to the milk mixture once or twice 
a day, increasing gradually to a tablespoonful at each feeding, 
if it is well tolerated. When the child is one year of age we 
may add stale bread-crumbs to the diet once or twice a day 
mixed with the milk or with meat broth; or the child may be 
given a hard crust of bread to chew. If signs of indigestion 
supervene, we must immediately reduce the amount of starchy 
food; it may be necessary to cut it off altogether if the diges- 
tive disturbance is marked. Some children cannot digest 
starch until the end of their second year. Fermentation of 
starchy food causes colic and diarrhoea, but seldom gives rise 
to marked constitutional disturbance, in contradistinction to 
the enteritis following "milk infection." 



172 THE ARTIFICIAL FEEDING OF INFANTS. 

Meat Broths. 
Mutton, veal, chicken, or beef broth may be given to the 
child when he is one year old. Their use is indicated before 
this time if the child has rickets or gastro-intestinal disturb- 
ances. One cupful (from six to eight ounces) of broth with 
the fat carefully removed may take the place of a milk feed- 
ing in the middle of the day. The broth may be thickened 
with a starchy gruel, or its nutritive value increased by the 
addition of the yolk of an egg (during the second year), or 
cream may be added to it for infants with weak digestions. 

Eaw Beef Juice. 
This is one of the most assimilable forms of albuminoid 
food. It can be given with safety to an infant over one year 
of age in doses of from half an ounce to an ounce. From one 
to three ounces may be given during the twenty-four hours. 
The administration of beef juice to infants under one year 
may be desirable in cases of rickets, scurvy, malnutrition, etc. 
One teaspoonful may be given once or twice a day to a child 
nine months old. 

Scraped Meat (Beef or Mutton). 
This can form part of the healthy child's diet during the 
second half of the second year. Eotch prefers not to begin 
its administration until the first half of the third year. One 
tablespoonful may be given once a day at the midday meal, 
to take the place of the beef juice. It should not be given 
to infants with weak digestion. Cautley allows white meat 
of chicken at this period. 

Yolk of Egg. 
This can be added to a pint of meat broth or to a starchy 
gruel. It is a convenient means of adding fat to the diet, but 
we must remember that it is not as easily assimilated as good 



WEANING. ] 73 

cream. Since the yolk of one egg contains thirty-two per cent, 
fat (Konig), it must be well diluted to render it digestible. 
A vigorous, healthy infant may be given the yolk of egg at 
the age of nine or ten months, but in the majority of cases 
it is well to wait until the child is from twelve to eighteen 
months old before making this addition to the diet. A soft- 
boiled egg may be given once or twice a week after the six- 
teenth month. Cautley allows custard at this age. 

Bread and Butter. 
A small slice of stale bread, plain or toasted and thinly 
buttered, is permissible after the first year, and may form 
part of the daily diet. Eye, Graham, or whole wheat bread 
may be used if the child is constipated. 

Eice, Potato, Hominy, etc. 
One large tablespoonful of well-boiled rice or hominy, mixed 
with milk, may be given to a healthy child for its dinner two 
or three times a week during the latter half of the second year. 
In place of it, the child may have one tablespoonful of thor- 
oughly baked well-mashed potato, with a little butter and 
salt. Beef gravy may take the place of the butter. Monti 
allows puree of peas. 

Green Vegetables. 
A small quantity of well-boiled spinach is allowed now and 
then by Monti and Cautley after the eighteenth month. Fen- 
wick gives occasionally a little stewed celery, well-cooked as- 
paragus tips, or cauliflower. 

Dessert. 
One or two tablespoonfuls of junket, custard, or plain rice 
and milk pudding may be given with the dinner to a healthy 
child during the second year. Cautley allows farina, and 
Fenwick sago and tapioca pudding. 



174 THE ARTIFICIAL FEEDING OF INFANTS. 

Fruit. 
Orange juice is a valuable addition to the child's diet and 
possesses antiscorbutic properties. It may be given in tea- 
spoonful doses, increased to one or two ounces at the end 
of the first year. Apple sauce, the soft part of two or three 
stewed prunes, or a slice of baked apple is admissible during 
the latter half of the second year. Botch allows a ripe peach 
at this age. 

Holt. 183 Milk should be the basis of the diet during the 
second year of life. The child should be weaned from the 
bottle by the thirteenth to the fifteenth month, except perhaps 
the night feeding. For the average case little modification 
of the milk is necessary unless it be very rich, when it should 
be diluted one-fourth or more, during the hot weather espe- 
cially. If the milk is poor in fat, use the upper two-thirds 
of the bottle. 

Farinaceous gruels may advantageously be added to the milk 
mixtures. The total quantity of liquid food to be given during 
the first six months of the second year should be from forty 
to fifty ounces a day; during the last six months this quan- 
tity should be increased to forty-five or fifty-five ounces. 

D. J. Milton Miller 109 advises that the diet in the second 
year should be largely nitrogenous with a minimum of carbo- 
hydrates, the latter to be given in the form of gruels or jel- 
lies. Bread must not be used before the end of the second year, 
unless crushed and mixed with milk; it must be well dried in 
the oven, or we may use zwieback instead. Of course many 
children can digest farinacea well during the second year; 
to insure the best results, however, we must be cautious in 
the administration of starchy foods, which are such a frequent 
cause of indigestion during the second and third years of the 
child's life. 

Jacobi. 76 Beef and meat broths may be given towards the 



WEANING. 175 

end of the first year, or at any time in rickets; mutton broth 
should be used if there is a tendency to diarrhoea. Beef tea 
contains much salt, and hence it is dangerous to give it in 
summer diarrhoea; it is low in albuminoids, and may be ren- 
dered more nutritious by the addition of farinacea or egg 
albumin. Beef broth is about as rich in albuminoids as whey ; 
it contains extractives, creatin, and creatinin. It should not 
be given when there is gastric irritation, gastritis, or acute 
dysentery. Veal broth is liable to increase diarrhoea and 
mutton broth to increase constipation. 

Peptonized beef preparations are valuable, but the condition 
of the digestive organs must be carefully considered. The 
last product of gastric digestion is albumose. The formation 
of peptone is not completed till the action of the pancreatic 
ferments and perhaps certain intestinal bacteria has mani- 
fested itself. Peptone can be formed without the presence 
of hydrochloric acid. Scraped raw beef is easy of digestion; 
it is of use in the chronic stage of, and during convalescence 
from, gastro-intestinal catarrh. 

White meat, such as chicken, contains less fat, haemoglobin, 
and extractives than beef. The white of egg alone may be 
valuable for temporary use, or it may be given as a permanent 
addition to other food. 

J. Eudisch has devised the following method of preparing 
milk for infants with gastric catarrh or who cannot digest 
milk in its usual form. He mixes from twenty-five to thirty 
minims of dilute hydrochloric acid with a pint of water, adds 
a quart of milk, and boils for a few moments. This prepara- 
tion keeps well, is palatable, and highly digestible. Bunker 
has recently called attention to this method. 

Somatose is worthy a trial because it does not contain those 
nucleins which irritate the kidneys and because it is a genuine 
albumose: one teaspoonful contains as much albumin as half 
an egg or three tablespoonfuls of milk. 

The artificial farinaceous foods, in which starch is more or 



176 THE ARTIFICIAL FEEDING OF INFANTS. 

less transformed into dextrin, fill a gap for those rare cases 
in which milk, though ever so well prepared, or the cereals, 
such as oatmeal and barley, are not well tolerated. 

Extract of malt contains albuminoids, fifty-three per cent, 
of sugar, and fifteen per cent, of dextrin; one tablespoonful 
of it is equivalent in nutritive value to one egg. It may be 
serviceable; it is very nutritious on account of its richness 
in sugar, and should be utilized oftener than seems to be 
usual. 

Monti " states that cereal coffee may be used as an addition 
to the milk in cases in which the digestion is poor (rickets, 
scrofula, etc.), and likewise cocoa. Neither contains enough 
fat or albumin to be of much nutritive value. Tea and coffee, 
especially black coffee, are useful stimulants for collapse and 
heart weakness in infants; in fact, in many cases they are 
preferable to alcohol. After the eighteenth month a small 
amount may be added to the milk without hurting the child 
and with no danger to the nervous system ( ? Editors). 

Alcohol is not needed normally. Used judiciously, it has 
decided value in furthering digestion in weak, sickly, and 
anaemic children. Brandy, wines (with a low percentage of 
alcohol), and beer may be used. 

Water should be given with each meal (from five to seven 
ounces at least). 

For purposes of comparison as well as clearness, we have 
tabulated the diet lists (during the second nutritive period) 
of Fen wick, Starr, and Cautley. 

Diet for the Second Nutritive Period (Twelve to 
Eighteen Months). 

First Meal from Six to Eight A.M. 
Starr. 133 A slice of stale bread soaked in a cup of fresh 
milk, or the lightly boiled yolk of one egg with bread-crumbs 
and milk. 



WEANING. 177 

Fen wick. 52 From eight to ten ounces of milk with a slice 
of thin bread and butter or rusk, or milk and a teaspoonful 
of Quaker oats. 

Second Meal from Nine to 10.30 A.M. 

Starr. Six ounces of milk with a thin slice of buttered 
bread or a soda biscuit. 

Cautley. 38 A bowl of thick gruel or oatmeal porridge, or 
a cup of cocoa and milk with bread and butter. 

Fenwick. Milk and rusk or plain biscuit. 

Third Meal from One to Two P.M. 

Starr. A cup of meat broth with a slice of bread and one 
tablespoonful of rice and milk pudding, or a mashed baked 
potato moistened with one or two ounces of beef tea, and two 
tablespoonfuls of junket. 

Fenwick. Tapioca or sago pudding may be used instead 
of the rice pudding, and a little stewed fruit may be given 
once or twice a week. 

Cautley. The lightly boiled yolk of an egg or a poached 
egg with stale bread; stale bread-crumbs in beef tea, soup, 
or broth, and a large tablespoonful of custard, corn flour, 
or blanc-mange. 

Fourth Meal from Five to Six P.M. 
Same as the first or second. 

Fifth Meal from Nine to Ten P.M. 
Starr. Half an ounce of Mellin's Food with half a pint 
of milk. 

Cautley. A cup of milk gruel made with rice, tapioca, 
sago, or hominy; or rusk or lady-finger. 

In Starr's opinion, the fifth meal is often unnecessary and 
the child should never be wakened for it. If the child wakes 
early in the morning, it should be given a cup of warm milk. 

12 



178 THE ARTIFICIAL FEEDING OF INFANTS. 

Diet foe the Second Nutritive Period (Eighteen Months 
to Two Years). 

First Meal from Seven to 7.30 A.M. 

Starr. Half a pint of fresh milk, the yolk of an egg, and 
two slices of bread and bntter. 

Cautley. One ounce of well-cooked oatmeal or wheaten 
grits with sugar and cream, and a glass of milk. 

Second Meal from 10.30 to Eleven A.M. 
Starr. Milk and bread and bntter or a soda biscuit. 
Fenwick. In addition to the above, treacle, sugar, or mar- 
malade. 

Third Meal from 1.30 to Ttuo P.M. 

Starr. Eight ounces of beef, mutton, or chicken broth with 
a slice of stale bread and butter and a saucer of rice and milk 
pudding ; or half an ounce of underdone mutton pounded to a 
paste, and a mashed baked potato moistened with dish gravy 
and a saucer of junket. 

Fenwick. Custard, tapioca, or rice pudding ; finely minced 
mutton-chop or a boiled egg; stewed celery, well-cooked as- 
paragus, or cauliflower may be given occasionally with dinner. 
When the first set of molars are cut, a small amount of boiled 
sole or cod or finely minced boiled fowl may be given. 

Cautley allows spinach, and Ashby and Wright 2 stewed 
apples and preserves. 

Fourth Meal at 6.30 P.M. 

Starr. A cup of milk with bread and butter, or toast, or 
milk toast. 

Fenwick. The yolk of an egg lightly boiled, or cocoatina 
(half a drachm to six ounces of milk), or treacle. 



CHAPTEE VII. 
CARE OF THE MILK. 

It is scarcely necessary to describe in detail the numerous 
ways in which milk may become contaminated during the 
process of milking. To those who are not familiar with the 
conditions at the average dairy farm, it is evident that when 
the udder and teats of the cow are not washed, and the hands 
of the milkers, the milk-pails, and utensils only hastily and 
imperfectly cleansed, the opportunities for milk infection are 
manifold. 

It is interesting to follow such milk from the time when it is 
drawn until it reaches the consumer; unfortunately, much the 
larger portion of the city's supply meets with the following 
treatment. The milk drawn in the morning, after being aerated 
by pouring from can to can, is taken from the various farms 
to the nearest railroad station, where it stands in its forty- 
gallon cans until removed to the distributing stations in the 
city. From these the various small milk dealers remove it as 
soon as feasible to their dairies. During this time no attempt 
has been made to keep the milk cool other than the use of a 
protector over each can in the wagon. 

With the morning's milk is also sent the milk of the pre- 
vious evening, which has been kept cool (probably from 50° 
to 54° F.) through the night. When the dairy supply is at a 
great distance from the city, the morning's milk is not sent 
to town until the following morning, it being then twenty-four 
hours old. 

As before said, the various small dealers remove their con- 
signments at once to their dairies, and from this time some 
of this grade of milk receives fair treatment, being at once 
cooled in ice-water and perhaps bottled, ready for delivery. 

179 



180 THE ARTIFICIAL FEEDING OF INFANTS. 

In the hands of less careful dealers, however, many further 
accidents befall it. 

The main delivery is made in the morning following the 
arrival of the milk in town, when it is from twenty-four to 
forty-eight hours old; during hot weather an extra delivery 
is made at noon. As might be expected, in summer weather 
such a product will necessarily become sour soon after delivery, 
and the temptation for the small dealer to use preservatives 
is in many instances too great to be resisted. 

The milk is delivered either in the can or in bottles. Un- 
fortunately, the practice of ladling the milk from the can 
on the " route" is still very prevalent, and it is easy to imagine 
the many additional means for its contamination during this 
process. The use of bottled milk is becoming more popular, 
however, and if the milk were only pure to begin with, many 
of the dealers could be trusted to fulfil fair requirements of 
cleanliness in distributing it. The practice of filling bottles 
on the wagon, although not the rule, is unfortunately quite 
common. The demand for bottled milk on a particular route 
may exceed the supply, and nothing is easier than to fill some 
of the bottles, returned by patrons, from the can, with no fur- 
ther precautions for the cleanliness of the bottles than the 
housewife has chosen to take ! 

It is needless to comment on such a practice, which has 
probably given rise to the principal objection made against 
bottled milk, — namely, the danger of contagion conveyed by 
the bottle. If the bottles are not thoroughly scalded and 
cleansed before refilling, they may thus prove to be even more 
dangerous than the large delivery can. 

The use of coloring matter and cream thickener is very 
general. They do less harm, perhaps, than preservatives, unless 
they are added to an ordinary milk and sold for cream, thereby 
cheating the customer out of his rightful fat percentage. An- 
notto, a vegetable product, is the principal form of coloring 
matter used, and a compound of powdered gelatin and boric 



CARE OF THE MILK. 181 

acid,, such as Heller's Cream Albumin, gives to " cream" its 
richness and consistency. 

From this short account it will readily be seen how many 
are the defects and how serious may be the dangers of the 
city milk-supply. In marked contrast to the ordinary supply 
of milk is that sold under the seal of the various milk com- 
missions which have been established in many of the larger 
cities. 

Before describing certified milk, however, it will be well 
to give a small part of the overwhelming evidence as to the 
extent to which milk may be contaminated with disease-pro- 
ducing micro-organisms. 

Estes 246 examined one hundred and eighty-six specimens 
of milk coming from all parts of England. The bacillus tuber- 
culosis was present in eleven cases (5.3 per cent.), doubtful 
in two cases. Pus was present in forty-seven cases (thirty 
per cent.), muco-pus in seventy-seven others (48.7 per cent.). 
Blood was present in twenty-four specimens; streptococci in 
seventy-five per cent, of all the cases. Eighty per cent, of all 
the samples contained pus, muco-pus, or streptococci, and were 
unfit for use. 

Additional instances of contamination with bacteria will 
be found in Chapter VIII. 

William E. Stokes and G-. Wegefarth, 245 investigating 
the microscopic appearance of milk, find that the occurrence 
of garget or inflammation of the udder in cows is not infre- 
quent, and that milk from such animals contains many pus- 
cells and organisms of suppuration. The studies of Booker 
and others strongly suggest that such milk can cause various 
forms of gastro-enteritis. 

The microscopic examination of milk will often draw at- 
tention to a condition which might otherwise escape notice. 
The authors carried out three series of investigations : 

(1) One hundred cows in the country under improved hy- 
gienic care. 



182 THE ARTIFICIAL FEEDING OF INFANTS. 

(2) Fifty cows in the country under poor hygienic care. 

(3) One hundred cows in the city, stall-fed and under poor 
hygienic care. 

The milk from Series No. 1 gave an average of 1.1 pus-cells 
to the microscopic field (one-twelfth objective) and practically 
no pus organisms. 

That from No. 2 gave an average of 11.3 pus-cells, and that 
from No. 3 gave an average of 19.2 pus-cells, while strepto- 
cocci were present in large numbers. 

The authors conclude that when pus-cells are found in 
large numbers in milk it should suggest a careful inspection 
of the herd. The standard for exclusion must necessarily be 
arbitrary, but an average of more than five pus-cells to the 
field with a one-twelfth oil immersion objective should ex- 
clude an animal from the herd. 

E. G. Freeman 179 in a recent article discusses briefly the 
diseases which can be transmitted in milk and the best means 
to avoid contamination. He classifies such diseases as fol- 
lows: 

I. Those in which the pathogenic germs that are introduced 
into the milk are conveyed from the body of the diseased cow, 
as tuberculosis, anthrax, foot-and-mouth disease, and acute 
enteritis. 

II. Those in which germs gain entrance from some other 
source either during or after milking, such as cholera, typhoid 
fever, scarlet fever, and diphtheria. 

III. Those caused by milk which contains poisonous agents 
developed by bacterial growth. 

In all these diseases, except anthrax, we have very conclusive 
evidence that the milk-supply may be the source of contagion. 
From the study of epidemics so caused Freeman draws the 
following lessons: 

I. Whenever a case of communicable infectious disease is 
reported, inquiry into the source of the milk-supply should be 
made. 



CARE OF THE MILK. 183 

II. Milk traffic should be carried on in houses separate from 
the dwelling-house; the dairy building should be at least one 
hundred feet from the dwelling-house, barn, or privy. It 
should be on a higher level of ground than any of these, and 
should have its own pure water-supply. All of the work of 
the dairy should be done in this dairy building, including the 
cleansing of the pails and cans. 

III. It should be unlawful for any one who has come in 
contact with a sick person (when the sickness is not positively 
known to be non-contagious) to enter the dairy building or 
barn or to handle the milk. 

IV. All employees connected with the milk traffic should be 
compelled to notify the authorities on the outbreak of any dis- 
ease in their abodes, and to abstain from work until permission 
to resume is granted them by the authorities so notified. 

V. Cities should accept milk only from those dairies which 
are regularly inspected and where all the cows have been tested 
with tuberculin, and where those which give the characteristic 
reaction have been killed and the premises disinfected. 

VI. The tuberculin test should be applied to all cattle, and 
those which react should be killed, the owner being reimbursed 
from State funds. The premises on which such tuberculous 
cattle have been kept should be thoroughly disinfected. All 
cattle which are brought into a State should be quarantined 
until the tuberculin test has been applied. 

VII. The use of one long trough for the purpose of feeding 
many cattle should be avoided, since it is a ready means for 
the conveyance of pathogenic germs from one animal to an- 
other. 

Undoubtedly, the adoption of such regulations would do 
much to reduce the amount of sickness conveyed by germs 
in milk. Freeman does not think that any regulations can 
entirely eliminate this danger. He concludes, therefore, with 
a word of caution in favor of the destruction of pathogenic 
germs by some process of sterilization. 



184 THE ARTIFICIAL FEEDING OF INFANTS. 

In this country steps have been taken in several of the large 
cities to provide a milk which shall come up to recognized 
standards of strength and purity. The pioneer attempts to 
thus standardize the milk-supply were made by Henry L. 
Coit, of Newark, New Jersey. 

Milk Commissions, consisting of three or more pediatrists, 
now exist in New York, Philadelphia, Baltimore, Boston, and 
Buffalo. 

The Commission of the Philadelphia Pediatric Society has 
established the following requirements: 

" 7. The Commission shall select a bacteriologist, a chemist, 
and a veterinary inspector. The bacteriologist shall procure 
a specimen of milk from the dairy or preferably from delivery 
wagons, at intervals to be arranged between the Commission 
and the dairy, but in no case at a longer interval than one 
month. The exact time of the procuring shall be without 
previous notice to the dairy. He shall test this milk for the 
number and nature of bacteria present in it, to the extent which 
the needs of safe milk demand. He shall also make a micro- 
scopic examination of the milk for pus-cells. Milk free from 
pus and injurious germs and not having more than ten thou- 
sand germs of any kind or kinds to the cubic centimetre shall 
be considered to be up to the required standard of purity. 

" 8. The chemist shall in a similar manner procure and ex- 
amine the milk for the percentage of proteids, fat, sugar, 
mineral matter, and water present. He shall also test its 
chemical reaction and specific gravity, and shall examine it 
for the presence of foreign coloring or other matters or chemi- 
cals added as preservatives. Standard milk shall range from 
1029 to 1031- specific gravity, be neutral or very faintly acid 
in reaction, contain not less than from 3.5 to 4.5 per cent, pro- 
teids, from four to five per cent, sugar, and not less than from 
3.5 to 4.5 per cent, fat, and shall be free from all foreign con- 
taminating matter and from all addition of chemical substances 



CARE OF THE MILK. 185 

or coloring matters. Richness of cream in fat shall be speci- 
fied, and shall vary not more than one per cent, above or below 
the figures named in selling. Xeither milk nor cream shall 
have been subjected to heat before the examination has been 
made, nor at any time unless so announced to the consumer. 

" 9. The veterinary inspector shall, at intervals equal to 
those of the bacteriologist and chemist, and without previous 
warning to the dairy, inspect the cleanliness of the dairy in 
general, the care and cleanliness observed in milking, the care 
of the various utensils employed, the nature and quality of the 
food used, and all other matters of a hygienic nature bearing 
upon the health of the cows and the cleanliness of the milk, 
including also, as far as possible, an inquiry into the health 
of the employees on their farms. He shall also see that the 
cows are free from tuberculosis and other disease. 

" 10. . . . Any dairy, the milk of which shall be found by 
the examiners to be up to the standard of the Commission, 
shall receive a certificate from the Commission. 

"11. In case an examination shows the milk not up to the 
standard, the dairy may have a re-examination made within a 
week or within a short time, at the discretion of the Com- 
mission. 

" 13. The dealers to whom certificates have been issued shall 
furnish milk to their customers in glass bottles, hermetically 
sealed in a manner satisfactory to the Commission. In addi- 
tion to the sealing, and as a guarantee to the consumer that 
the examination has been regularly conducted, there shall be 
pasted over the mouth of the jar, or handed to the consumer 
with every jar, according to the discretion of the Commission, 
a certificate slip. . . ." 

The inspection and analysis of certified milk are most thor- 
ough, since not only the hygienic cleanliness of the milk but 
also the percentage of its ingredients must be determined. 



186 THE ARTIFICIAL FEEDING OF INFANTS. 

To insure a uniform standard in the constituents of milk, 
careful selection of the cattle is required and an equal care 
in their feeding and daily hygiene. The best breeds of cows 
available for infant feeding in this country, according to 
Botch/ 19 are the Durham, Devon, Holstein-Friesian, Ayr- 
shire, Bretonne, and Brown Swiss. The red cows in this 
country do not come up to the standard, owing to their lia- 
bility to gastro-intestinal disorders. The famous Jersey and 
Guernsey cows furnish a rich milk, but they are more liable 
to contract tuberculosis (when transported from the Channel 
Islands to a more severe climate) than the breeds above men- 
tioned. Some dairies require a two months' quarantine for 
Jersey and Guernsey cows before applying the tuberculin test. 

Botch 119 declares that cows which furnish milk for infant 
feeding should possess the following characteristics: 

I. Constitutional vigor. 

II. Adaptability to acclimatization. 

III. Notable ability to raise their young. 

IV. Freedom from intense in-breeding. 

V. Distinct emulsification of the fat in the milk. 

VI. A preponderance in the fats of the fixed over the vola- 
tile glycerides. 

Volatile glycerides do not exist in the mammae, but form in 
the milk soon after milking, especially in the case of Jersey and 
Guernsey cows. 

Cautley. 38 The failure of cow's milk to give satisfaction 
as an artificial food may be due to one or more of the follow- 
ing conditions: 

I. A faulty condition of the cow, such as excessive age, pro- 
longed lactation, recent calving (the milk containing colos- 
trum corpuscles), etc. 

II. Diseases of the cow, such as pneumonia, foot-and-mouth 
disease, diseases of the udder, etc. 

III. Improper feeding and care of the animal. 

IV. Improper or careless milking. 



CARE OF THE MILK. 187 

V. Improper handling of the milk before it reaches the con- 
sumer. 

VI. Improper composition of the milk, snch as deficiency 
in fat. etc. 

Monti " says : " To get proper milk of stable composition 
the cow shonld have calved three months* previously, and only 
the milk obtained during the next four months should be 
used; after this the milk contains too much casein and too 
little sugar and fat." 

Taylor and Wells 147 give the third to the ninth year of 
the cow's life as the best period of lactation. 

Kliiumee S5 states that the liability to tuberculosis in- 
creases with the age of the cow, and that tuberculosis is 
especially prevalent during the best years of lactation. 

X[ilk should not be used until free from colostrum cor- 
puscles, nor during advanced gestation. During the cata- 
menia it is probably unfit for infant feeding, but this objec- 
tion scarcely applies if the mixed milk of the herd is used. 

The next most important factors for the production of clean 
milk are the care of the covr and cleanliness in the process of 
milking. 

Eotch says that the barn should have a capacity of at least 
twelve hundred cubic feet of air for each cow: light and venti- 
lation are essential, especially in the prevention of tuberculosis. 
Whenever the weather permits, the cows should be turned out 
in the sunning yards when not being milked. These yards 
should drain away from the barn, the water-supply, and the 
milk-house. The fittings, troughs, floor, etc., of the barn should 
be of impervious material capable of being thoroughly cleansed 
with water; the floor should drain well to remove excreta. 
The stall should be wide enough to allow freedom of motion 
for the cow. The bedding should be fresh and free from 
mould or any soil productive of bacterial growth. At the 
Walker-Gordon farm at Chestnut Hill, Pennsylvania, they find 
that shavings answer the purpose admirably. Whatever the 



188 THE ARTIFICIAL FEEDING OF INFANTS. 

material selected, it should be changed before milking, — twice 
a day. 

The cows should be treated with a proper amount of con- 
sideration, especially before the milking hours. Fright and 
unusual excitement must be avoided, as they are apt to disturb 
lactation or may even suppress it. The water-supply for the 
herd must be above suspicion: it is best that each cow have 
a separate drinking-trough in which the water can be renewed 
frequently. 

One part nitrogenous to five and a half or six parts non- 
nitrogenous is the proper ratio in the cow's fodder to produce 
the milk best suited for the infant's needs. The nitrogenous 
elements are found in clovers, beans, peas, vetches, wheat 
bran, etc., while timothy, rye, Kentucky-blue, maize meal, 
and oat straw represent the non-nitrogenous. In the green 
state most of the grasses afford a fairly balanced nutriment, 
but care must be exercised in changing from fresh to dry 
rations, owing to the changes which this causes in the compo- 
sition of the milk, thereby interfering with its proper diges- 
tion. 119 

Plenty of food and little exercise increase the yield of 
milk. 38 Nitrogenous foods increase the fat 3S and the casein- 
ogen. 52 Carrots and beet roots increase the sugar of milk. 52 
The refuse from breweries and distilleries makes milk abun- 
dant in quantity but deficient in solids. Diseased potatoes or 
turnips give an unpleasant taste and smell. 52 

Cautley considers that, on the whole, pasture-fed cows are 
apt to produce a milk better suited for the infant than that of 
stall-fed animals. Grass-fed cows are apt to have alkaline or 
nearly alkaline milk. Those fed in stalls on dry fodder and 
grain usually give milk of an acid reaction. 119 

Gordon has found that Austrian sugar-beets, in the pro- 
portion of ten pounds daily per cow, as part of the non- 
nitrogenous element of the diet, made the milk neutral or 
slightly alkaline. This reaction persisted for several hours at 



CARE OF THE MILK. 189 

the ordinary temperature. One- third of the milk from the 
cows so fed, when added to two-thirds of the mixed milk of 
a herd fed on ordinary diet, caused a neutral or slightly alka- 
line reaction. 119 

In order to obtain milk in an approximately sterile condi- 
tion several things are necessary. The cow's udder, abdomen, 
flanks, and groins should be well groomed, and during the hot 
weather the hair should be clipped. In addition to this, before 
each milking, they should be thoroughly washed, preferably 
with a 1 to 1000 bichloride solution, and carefully dried. This 
process should include the teats as well. During the summer 
time particles of dirt fall into the milk-pail from the switching 
of the cow's tail in driving off the flies. Care should therefore 
be taken to prevent as far as possible the entrance of flies into 
the barn, and by the use of narrow-mouthed milk-pails to 
avoid contamination from the air and the sides of the cow. 

The milkers should be dressed in clean sterile white suits 
and caps. Their hands and arms should be thoroughly 
scrubbed and dried before each milking; in some dairies the 
use of sterilized cotton gloves is advocated. No one suffering 
from, or who comes in contact with, any infectious disease 
should be allowed to perform any duties in connection with 
the dairy farm. 

In the milking process sufficient force should be exerted to 
imitate suction by the calf, and at each milking every drop 
should be withdrawn. The first few drops or streams should 
always be discarded, so that the milk-ducts may be washed free 
from bacteria. 

The milk-pails may be of a variety of designs, but a long, 
narrow pail offering a small surface for air contamination, 
and with rounded corners and edges to insure easy and com- 
plete cleansing, embodies all the essentials. As soon as the 
pail is filled it should be carried to the milk-house. 

The following is a description of the milk-house at the 
Walker-Gordon farm near Philadelphia. 



190 THE ARTIFICIAL FEEDING OF INFANTS. 

The milk-house is situated far enough from the barn to be 
free from all odors. Its construction insures thorough ventila- 
tion ; the windows and doors are all protected with fly-screens. 
The milk-house is divided into three rooms, — the engine-room, 
the washing- and sterilizing-room, and the milk-room proper. 
The floors are of concrete to allow of flushing. 

The milk-cans, when filled, are brought from the barn and 
emptied into a covered receptacle set in the wall of the milk- 
room. This is further protected from the air and dust by a 
shed; in this shed are also steam faucets over which the cans 
are inverted and filled with live steam before using again. 
The milk runs from this receptacle through a pipe in the wall 
of the milk-room directly to the aerator and cooler, and is 
strained through eight thicknesses of sterile gauze on the way. 
This obviates the necessity for the milkers to have access to the 
milk-room. 

The milk runs down from the pipe over a corrugated zinc 
plate which is cooled by a set of ice-water tubes under it, and 
then drops into a porcelain tub, from which it can be drawn 
off and bottled. This aerating process reduces the tempera- 
ture to about 60° F. The milk is then bottled, sealed with 
sterile pasteboard caps, placed in ice-water, and kept at a tem- 
perature of from 45 ° to 50° F. until ready for delivery. 
During the heated term the bottles are packed in cracked ice 
before being placed in the wagon. 

A portion of the milk-supply of the Walker-Gordon plant, 
instead of being bottled, is run through the separator and 
the cream shipped to town for use in the Milk-Laboratory. 
The morning's milk can be delivered within eight hours of 
being drawn, the evening's product never arriving later than 
from twelve to eighteen hours after milking. 

When the bottles are returned from the consumers they are 
thoroughly washed in water containing soda and are then 
sterilized with live steam for thirty minutes. The porcelain 
tub into which the milk falls from the aerator can also be cov- 



CARE OF THE MILK. 191 

ered and sterilized with steam. By these means all possible 
chances for contamination are rigorously excluded. 

The experiments of Peters 119 seem to prove that a prac- 
tically sterile milk can be obtained, provided the proper pre- 
cautions are carried out. Four cows were used in these ex- 
periments. The milker was dressed in a sterilized white suit 
and cap. and his hands and arms thoroughly washed with a 
1 to 1000 bichloride solution. The cows' udders, teats, flanks. 
sides, and abdomens were washed with the same solution and 
dried with a sterile towel, and the milk was received in sterile 
bottles. 



>o. of colonies of bacteria 
per cubic centimetre. 

No. I. Milk of the first half received by hand 

directly into the bottle 141-167-11—53 

No. II. Milk of the first half drawn by a sterile 

canula into the bottle 0-0-1-2 

Xos. III. and TV. Drawn by hand after more than ( 0-6-0-0 

half the udder had been emptied ( 0-0-1-2 



The bacteria in Xo. 1 may have come partly from the air, 
but most likely from the teats, which had become infected 
through their orifices with ordinary forms of cocci and bacilli. 
The hands of the milker may also have carried infection. 

TTe have taken as our standard for the description of what 
the dairy farm should be the works of Eotch and Cautley and 
our own observation of the Walker-Gordon farm. This shows 
what is being done in the dairies which have accepted the 
standard set by the Philadelphia Milk Commission. It is 
interesting to note that the American standard for certified 
milk is equal if not superior to that of any other country. 

Certified milk will probably command a higher price than 
average milk, at least for a long time : but it is not too much 



192 THE ARTIFICIAL FEEDING OF INFANTS. 

to hope that with the increase of competition the general 
public will eventually obtain an approximately clean product 
of moderate price and infinitely superior to that which we 
have hitherto been forced to accept. 

In view of the well-known excellence of the dairy products 
of Denmark it is worth our while to study the method of 
handling milk which is carried out in Copenhagen, Denmark. 

The milk is brought to the company by various farmers, 
and only sound milk is received. By the regulations, the milk 
of any sick cow is paid for at the regular rates, also the 
wages of any employee who is suffering from an infectious dis- 
ease. The milk is supplied to the consumer in sterilized bottles 
closed with clean new corks. The company guarantees veteri- 
nary control of all cows from which the milk is obtained and 
the exclusion of that from suspected animals; also the cool- 
ing of milk to 40° F. or lower at the farms and depots; also 
the purification of the total product by upward filtration 
through fine gravel ; also absolute cleanliness of all bottles and 
cans which are stamped with the company's seal. The cows 
are inspected once every two weeks by a veterinary surgeon, 
and an inspector reports monthly on the fodder, state of the 
sheds, and the care exercised in the milking. During the 
summer the cows get fresh pasture, grass, and clover; in the 
winter, ha}^, oats, bran, and carrots. 

The following is an extract from the regulations: 

" The food of the cows must be of such a character that no 
bad taste or taint may be imparted to the milk by it. Brewers' 
grains and all similar refuse from distilleries are distinctly for- 
bidden, as is also every kind of fodder which is not fresh and 
in good condition. Turnips and turnip leaves are strictly 
forbidden. Carrots and mangolds are allowed up to one-half 
bushel for each cow, but only when at least seven pounds of 
corn, bran, and cake are also given. Eape-seed cake is the only 
oil-cake which may be used. Stall feeding in summer is not 
allowed under any circumstances. Cows must be fed in the 



CARE OF THE MILK. 193 

open air on grass and clover. Vetches are forbidden. In the 
autumn the cows must be clipped on the udder, tail, and hind 
quarters before being taken in. The milk of cows newly calved 
must be withheld for at least twelve days, and must be not 
less in quantity than three quarts a day. Immediately after 
milking, in all seasons, the milk must be cooled to 40° F. in 
ice-water." 

George T. Palmer, 217 in the Philadelphia Medical Journal, 
describes the Trinity Diet Kitchen which has been established 
in Chicago to supply a pure, modified, unheated cow's milk for 
infants in the poor district. 

The milk is obtained from the farm of H. B. Gurler, of 
De Kalb, Illinois. Much the same precautions as those de- 
scribed by Eotch in relation to Laboratory Milk are employed 
on this farm. The cattle are mainly of Holstein breed, tuber- 
culin tested, and carefully fed. Any cow which becomes sick is 
at once isolated from the herd in a separate building, etc. By 
a rapid process of cooling within from ten to twelve minutes 
after milking the temperature of the milk is reduced to 
45° F., and within twenty minutes after milking it has been 
bottled and sealed. Such milk has been kept on ice in the 
Diet Kitchen for almost two weeks without souring. Not one 
ounce of either sterilized or pasteurized milk has ever been 
distributed from this Diet Kitchen. A plentiful supply of 
ice with each bottle, and rigid instructions to the parents 
with regard to absolute cleanliness in handling the milk, keep- 
ing it cold, and regularity in feeding, contributed largely to 
the good results obtained. 

The following account of milk inspection as carried out 
by the New York Board of Health is given by Herman 
Betz 202 in the Medical News for March 10, 1900. 

The inspection is carried out by a corps of " milk inspectors" 
who make visits at short intervals to all of the dairies in their 
respective districts. If the milk prove unsatisfactory by the 
lactometer and thermometer tests, a sample is taken for analy- 

13 



194 THE ARTIFICIAL FEEDING OF INFANTS. 

sis. This analysis includes the determination of (a) the per- 
centage of water, (b) the total solids, (c) the fat, (d) the 
solids not fat, (e) the percentage low in solids, (/) the per- 
centage low in fat, (g) the reaction, and (h) the presence of 
preservatives, such as borax, salicylic acid, or formaldehyde. 
The retail dealer does not receive his permit until the inspector 
has satisfied himself that the shop and premises are in satis- 
factory condition, and that hygienic cleanliness of the appli- 
ances has been obtained. If the dealer fails to maintain 
hygienic precautions, or if the milk analysis shows that it is 
more than five per cent, low in solids or three per cent, low in 
fat, or contains preservatives, the permit for its sale is either 
withheld or withdrawn until the requirements are met. 

The wholesale dealer is required to give a list of the farms 
from which he obtains his supply, the breeds of cows employed, 
the precautions used in handling the milk, and the railroads 
on which it is shipped. In case of an epidemic of sickness 
occurring in any of the towns from which New York draws its 
milk-supply, notification is made to the Board of Health, and 
that portion of the supply, if in any way liable to infection, 
can be stopped. Each wagon of the wholesale dealer is re- 
quired to have a separate permit, and the name and address 
of the driver is kept on file. Each permit, in store or wagon, 
must occupy a conspicuous place. 

Edward B. Voorhees, in a Eeport on Food and Nutrition 
Investigations (abstract in the Dietetic and Hygienic Gazette, 
No. 13, 1897), asserts that the price of milk should be gov- 
erned by its fat content. It is entirely practicable, under 
present conditions, for even the smaller producers and dealers 
to guarantee a product containing a reasonably definite quan- 
tity of fat, because the chief causes of variations in the quality 
of the milk are well known, and inexpensive instruments, sim- 
ple in operation, are available for testing its fat content. 

Huddleston". 72 The two kinds of cream furnished in New 
York City are gravity, hand-skimmed or Cooley cream, and 



CARE OF THE MILK. 195 

machine-skimmed or separated cream. The former has an 
average fat percentage of from twelve to sixteen; it is raised 
in Cooley cans to allow of drawing off the milk from below 
after it has been submerged in cold water for twenty-four 
hours. It is said to keep poorly, and a compound of borax 
and salicylic acid called " Preservitas" is often added thereto. 
Machine-skimmed cream or separated cream is quickly pre- 
pared and keeps well. Most cream is at least seventy-two 
hours old before it reaches the city. A surplus supply is often 
kept buried in ice for a considerable period. Certain dairies, 
however, send cream to the cities bottled and sealed while 
fresh. Cream thickens with age; during periods of cold 
weather it is a common practice to hold it back so that it 
may appear richer. This increase in density is due to the 
multiplication of bacteria. 

Huddleston advocates the selling of milk and cream of known 
guaranteed fat percentages, and can find no reason why dealers 
should not supply cream as fresh as milk. Pasteurization 
can be practised at small cost at the dairy. 



CHAPTEE VIII. 
BACTERIOLOGY. 

That milk will sour if exposed to the air for a certain 
length of time is a fact so well known that it scarcely needs 
repetition, but it is only within recent years that we have been 
able definitely to determine the causative agents of this acidi- 
fication, — namely, certain species of bacteria. We know also 
that the clots formed in this process will under certain con- 
ditions redissolve as the result of bacterial action. It is 
probable that further changes in milk occur from the pres- 
ence of micro-organisms, but our knowledge on this subject is 
still in its infancy. At least we know that many of the prod- 
ucts resulting from the presence of acid-producing bacteria 
in milk are distinctly harmful to the infant organism. While 
it is possible that some species of bacteria may be of service 
in preparing milk for the chemical changes it must undergo 
before it is ready for absorption, on the whole the harmful 
far exceed the helpful varieties of milk bacteria. It is fair, 
then, to assume that the freer a milk is from micro-organisms 
the more suitable it will be for the needs of the infant. 

It is of course true that sterile milk becomes infected with 
bacteria as soon as it enters the mouth and the gastro-intestinal 
tract. When there is digestive disturbance, however, we will 
have reduced the etiological factors of disease by a very im- 
portant item if we are able to exclude contamination of the 
milk-supply. 

It must not be forgotten, in dealing with a milk which has 
well matured, that the ordinary methods of sterilization will 
destroy the group of lactic acid bacteria and leave the proteo- 
lytic or peptonizing group unharmed, and that toxic products 
may result from the presence of excessive numbers of pep- 
196 



BACTERIOLOGY. 197 

tonizing bacteria. Since these two groups are naturally an- 
tagonistic, it may prove a questionable advantage to overthrow 
the balance between them. This in no wise changes the origi- 
nal dictum that milk should have a low bacterial content to 
be an ideal food for infants. Such milk requires no other 
preservative than a low temperature, and no objection has yet 
been offered to its use. 

In the following pages we shall attempt to give a brief out- 
line of what has been done in that branch of bacteriology which 
concerns itself with the micro-organisms found in milk. 

Bacteria are found in the meconium within four hours after 
birth, from infection through the rectal orifice; somewhat 
later they gain entrance to the mouth from the air, bathing 
water, etc. 7 

S chill (Zeitschrift fur Hygiene und Infect. Krankheiten, 
Bd. xix., 1895) and von" PuTEREisr (quoted by Mannaberg in 
his work on Intestinal Bacteria, Vienna, 1895) consider that 
no amount of sterilizing can prevent the entrance of bacteria 
into milk faeces, even when the milk does not contain them. 
Infection probably comes from the swallowing of saliva. Lan- 
germann and Eberle have shown that almost sterile food will 
become infected through the stomach and intestines. 

Langermann" found that the infant's stomach normally con- 
tained from 3700 to 240,000 bacteria, in nursing children from 
6960 to 20,000, in the sick incomparably more, and, even in 
the presence of free hydrochloric acid, there were from 3200 
to 6400. Free hydrochloric acid is not found constantly in 
the infant's stomach; it can serve only to diminish and not to 
suppress bacterial growth (Jahrbuch fur KinderkrankJieiten, 
Bd. xxxv.). 

Eberle counted 33,000,000 micro-organisms in one milli- 
gramme of fresh faeces (only 1,500,000 to 3,000,000 by cul- 
ture), even when sterile food was used (Centralblatt fur 
Bacteriologie und Parisitenkunde, Bd. xix., 1896). 

Miquel 105 has estimated the rapidity with which bacteria 



198 THE ARTIFICIAL FEEDING OF INFANTS. 

multiply in cow's milk. The specimen contained 9000 bac- 
teria in each cnbic centimetre on its arrival at the laboratory 
two hours after milking. 

One hour later it contained 21,750 

Two hours later it contained 36,250 

Seven hours later it contained 60,000 

Nine hours later it contained 120,000 

Twenty-five hours later it contained 5,600,000 

Heat favors the multiplication of bacteria. In the same 
milk, after fifteen hours' exposure at 15° C, Miquel found 
100,000 bacteria per cubic centimetre, while at 25° C. there 
were 72,000,000, and at 35° C. 165,000,000. 

Sedgewick and Batchelder, 69 in Boston in 1892, found an 
average number of 70,000 bacteria per cubic centimetre of milk 
handled in the usual way and examined a few hours after milk- 
ing. In fifty-seven samples of milk taken from the ordinary 
delivery wagons they found an average of 2,355,000 bacteria. 

Backhaus's investigations 85 show to what extent different 
factors contribute in influencing the bacterial contamination 
of milk. 

Milking. 

Dry milking 5,600 germs per cubic centimetre 

Wet milking 9,000 germs per cubic centimetre 

First milk 10,400 germs per cubic centimetre 

Last milk Sterile 

Care of the Cow. 

When the cow is cleaned 20,600 germs per cubic centimetre 

When the cow is not cleaned 170,000 germs per cubic centimetre 

Udder washed 2,200 germs per cubic centimetre 

Udder not washed 3,800 germs per cubic centimetre 

Air Contamination. 
If the cow is milked in the open air. . 7,500 germs per cubic centimetre 
If the cow is milked in a clean stall. . 29,250 germs per cubic centimetre 
If the cow is milked in an unclean stall 69,000 germs per cubic centimetre 



BACTERIOLOGY. 199 

Vessels used. 

Enamelled vessels 1,105 germs per cubic centimetre 

Tin vessels 1,690 germs per cubic centimetre 

"Wooden vessels 279,000 germs per cubic centimetre 

Glenn Vessels. 

Sterilized vessels 1,300 germs per cubic centimetre 

Washed vessels 28,600 germs per cubic centimetre 

Infection. 

Fresh milk 6,660 germs per cubic centimetre 

Milk passed through six vessels 97,600 germs per cubic centimetre 

Straiv. 

Turf 40,000 germs per cubic centimetre 

Good straw 150,000 germs per cubic centimetre 

Dirty straw 200,000 germs per cubic centimetre 

Water. 

Eresh water 322 germs per cubic centimetre 

Trough water 228,200 germs per cubic centimetre 

Milk supplied from a good dairy farm 25,000 germs per cubic centimetre 
Milk supplied to the Konigsberg 

market 2,000,000 germs per cubic centimetre 

Catttley. 38 Human milk is usually considered sterile when 
there is no local disease of the breast. This is doubtless true 
of the milk contained in the gland. Escherich found the milk 
of twenty-five healthy women absolutely devoid of micro-organ- 
isms. On the other hand, Cohn and Neumann found microbes 
in the milk of forty-three out of forty-eight healthy women. 
The varieties of organisms most commonly present were the 
staphylococcus pyogenes, albus and aureus, and the strepto- 
coccus pyogenes. Honigmann made seventy-six examinations 
of the milk of sixty-four women, recently confined, and found 
it sterile on four occasions only. Eingel examined the milk 
of twelve healthy and thirteen ill nursing women, and found 



200 THE ARTIFICIAL FEEDING OF INFANTS. 

it sterile in three only. The microbes are most numerous in 
the milk first secreted, and in all probability have made their 
way along the ducts in the nipple. The milk last poured out 
is quite sterile. 

Marfan. 105 We may safely conclude that the milk of 
healthy mothers, obtained under aseptic precautions, contains 
micro-organisms nineteen times out of twenty. These are usu- 
ally the staphylococcus albus or aureus (Honigmann, Paleske, 
Kingel, Knochenstirn, G-enoud, Charrin, Trinci). These in- 
vestigators are agreed in recognizing that only the first por- 
tions of the milk obtained contain micro-organisms, and that 
these organisms are found only at or near the orifices of the 
lactiferous channels and not in the depth of the gland; hence 
they are not the result of elimination by the mammary gland. 
They come either from the skin near the orifices in the nipple 
or from the infant's mouth. 

These remarks as to the frequency of infection of woman's 
milk through the nipples apply equally well to cow's milk, 
only in the latter case the liability to infection is even greater. 
Lehmann and Schultz were among the first to demonstrate that 
cow's milk is practically never sterile. 

The microbes which are found in cow's milk ordinarily gain 
entrance in one of the two following ways: most often they 
are introduced during the act of milking and the manipulations 
following it; less commonly the milk is rendered virulent by 
the presence of the germs of an infectious disease from which 
the cow is suffering. The first are the ordinary saprophytic 
germs which are universally distributed throughout nature and 
are not pathogenic; but they spoil milk and render it more 
or less toxic. Exceptionally, accidental infection of milk with 
pathogenic germs may occur. 

The Saprophytic Microbes of Milk. 105 
Apart from infection of milk by organisms which make their 
way into the ducts of the nipple (which is of minor importance) , 



BACTERIOLOGY. 201 

there are many fruitful sources for its further contamination. 
Soxhlet has isolated, in cow's milk, the following impurities : 
faeces, dust, and particles of hay, grass, and straw. Infection 
may also occur from the hands or person of the milker, from 
particles of dirt, hairs, etc., brushed from the animal's flanks 
and udder, and from the receptacles into which the milk is 
drawn. Substances added to milk, such as water, coloring 
matter, etc., may lead to infection. Marfan considers that 
infection from the air is of less importance than was formerly 
thought. 

Lactic Acid Bacteria. 1 ®' 

The most frequent modification which milk undergoes is 
lactic acid fermentation. If fresh milk is allowed to stand, 
it first becomes acid in reaction and of a bitter taste. At the 
end of a period varying from one to four days, according to 
the temperature, coagulation occurs. This is due to the trans- 
formation of the lactose into lactic acid; from seven to eight 
per cent, of the latter is sufficient to coagulate the casein. 
When milk is heated, a smaller quantity of lactic acid is re- 
quired for its coagulation. 

Pasteur ascribed the transformation of lactose into lactic 
acid to the activity of a microbe which he called the " lactic 
ferment." This seems to be identical with the organism de- 
scribed by Htippe as the " bacillus of lactic acid." 

Leudet and Wurtz have established the identity of the " lac- 
tic ferment" with the bacillus lactis aerogenes of Escherich, 
and this, in turn, is closely allied to the bacillus coli communis 
of Escherich, which also causes lactic acid fermentation. 

Marfan considers that the usual lactic ferments probably 
represent different varieties of the bacillus coli communis 
which are normally found in the intestine. Ordinarily they 
are saprophytic, but under certain conditions they may become 
pathogenic. 

Freudenreich has collected the following list of organisms 
which cause lactic acid fermentation: the bacterium acidi 



202 THE ARTIFICIAL FEEDING OF INFANTS. 

lactiei of Grotenfeld; the micrococcus lactis I and II of 
Hiippe, the micrococcus acidi lactiei of Marpraann, the strepto- 
coccus acidi lactiei of Marpmann, the micrococcus acidi lactiei 
of Kriiger, the streptococcus acidi lactiei of Grotenfeld, and the 
bacillus prodigiosus. 

Certain pathogenic bacteria can acidify and coagulate milk : 
the staphylococcus pyogenes, the pneumococcus of Talamon 
and Frankel, the micrococcus of contagious mammitis of the 
cow (Nocard and Mollereau), the micrococcus of gangrenous 
mammitis of sheep (ISTocard), and the cholera bacillus (Netter, 
de Hann, A. C. Huysse). The streptococcus of erysipelas 
acidifies milk without coagulating it (Loffler). 

In the Twelfth Annual Eeport of Storr's Agricultural Ex- 
periment Station, Connecticut (1899), H. W. Conk has pub- 
lished a " Classification of Dairy Bacteria" which comprises 
the results of his investigations for the past ten years. Over 
two hundred different types of bacteria have been found which 
may be regarded as more or less distinct from one another. 
In his description he has followed as closely as possible the 
method adopted by Fuller and Johnson in their recent pub- 
lication on water bacteria, and has therebv endeavored to 
establish a uniform system of classification which shall serve 
as a basis for bringing together the work of American dairy 
bacteriologists. The need for such a system can scarcely be 
overestimated, as without a standard for comparison the work 
of many individual observers must go for naught. 

Conn concludes that the dairy organisms of New England 
are chiefly of four species, or, more strictly, three groups of 
closely related bacteria, namely, — 

The bacterium acidi lactiei of Esten. This variety is very 
generally found in samples of milk and cream from a wide 
area of territory. In sour milk it is almost always present. 
Its frequent occurrence in milk, together with its markedly 
anaerobic character, would seem to indicate that it probably 
comes from the milk-ducts. Conn's recent experiments (draw- 



BACTERIOLOGY. 203 

ing the milk directly from the teats into sterilized vessels, 
with little or no chance for contamination) seem, however, 
to point to the conclusion that this organism comes from 
external contamination. 

The variety of micro-organism next in frequency is No. 202 
on the list. This species differs only slightly from the bac- 
terium acidi lactici, and the two species undoubtedly belong 
together. They represent a type of dairy organism common 
everywhere. Many of the lactic acid organisms hitherto de- 
scribed by different bacteriologists clearly belong to this type, 
although slight differences in described characteristics perhaps 
indicate different varieties. This is true of the bacterium 
acidi lactici of Gunther and Thierfelder, bacterium lactis acidi 
of Leichmann, bacillus XIX of Adametz, bacillus a of von 
Freudenreich, micrococcus acidi hevolactici and bacillus acidi 
laevolactici of Leichmann, and several types described by 
Storch. 

The next most important dairy species described by Conn is 
No. 208, which he regards as identical with the bacillus lactis 
aerogenes. This is found almost universally, although never 
in very great numbers. It is quite possible that a number of 
distinct types are included under this head, as the organisms 
have shown wide variations. The distinctive characteristics 
of these species are : ( 1 ) the intense acid produced in litmus 
gelatin; (2) the abundant production of gas in milk-sugar, 
bouillon, or milk; (3) the uncertainty as to their power of 
curdling milk, this occurring commonly at high temperatures, 
though not at the temperature of the room; and (4) the 
distinctive odor of sour milk which they produce after cur- 
dling. 

According to Conn's observations, ordinary sour milk is pro- 
duced by the three organisms mentioned, and probably in the 
spontaneous souring of milk all three are present. 

It is probable that there belong to this group also the origi- 
nal bacillus acidi lactici of Hiippe, the bacterium lactis acidi 



204 THE ARTIFICIAL FEEDING OF INFANTS. 

of Marpmann, the bacillus acidi lactici I and II of Grotenfeld, 
No. 8 of Eckels, and doubtless several others. 

Finally, Conn describes the micrococcus lactis varians. This 
species is common in fresh milk and probably exists in the 
milk-ducts. It is often overgrown by the lactic organisms and 
is less often found in old milk. 

Peptonizing Bacteria. 

105 rp^g f ermen t s of casein or peptonizing bacteria are sapro- 
phytes belonging to the groups of which the bacillus subtilis 
and bacillus mesentericus vulgatus are the prototypes. These 
microbes act on casein through the products which they secrete. 
They coagulate casein without acidifying the milk by the aid 
of a ferment resembling lab, and they liquefy the coagulum 
and peptonize it by means of a ferment called " casease" (Du- 
claux). The peptone resulting from this is called " caseone." 
It is only at the end of lactic acid fermentation that the activity 
of the peptonizing bacteria begins. 

The ferments of casein comprise several species of microbes, 
of which the most important are the bacillus subtilis (hay 
bacillus), the bacillus mesentericus vulgatus (potato bacillus), 
and the tyrothrix group. The bacillus subtilis and the bacillus 
mesentericus vulgatus are aerobic organisms and universally 
distributed. These two species are poorly denned and many 
varieties can be included among them. The characteristics of 
these ferments are, that they utilize the casein after the first 
steps of digestion have rendered it assimilable, and transform 
it into various products which are found wherever microbes 
are acting upon albuminoids, — namely, leucin, tyrosin, urea, 
ammonium carbonate, acids of the fatty acid series (formic, 
acetic, propionic, butyric, valeric), ammonia and ammoniacal 
compounds, carbonic acid, water, hydrocarbon gases, hydrogen, 
and nitrogen. 

Nearly all the peptonizing bacteria produce spores which 
can resist temperatures higher than 100° C. Fliigge and 



BACTERIOLOGY. 205 

Llibbert have utilized this property for the isolation and study 
of the peptonizing bacteria, several varieties of which they 
have proved to be pathogenic. Lesage has also encountered 
in fermented milk a bacillus mesentericus with pathogenic 
properties. 

The bacillus subtilis and bacillus mesentericus vulgatus are, 
as a rule, not found in the faeces of the breast-fed infant. When 
they are present, they are not numerous unless digestive trou- 
bles exist; usually they are not virulent (Marfan). 

Flugge. 199 Enormous numbers of peptonizing bacteria can 
be present in a milk which is apparently normal and free from 
germs. Flugge asserts that the peptonizing and the most re- 
sistant anaerobic bacteria are not destroyed, though subjected 
to a temperature of 100° C. for three-quarters of an hour. 
If such a milk is kept for several days at a temperature ex- 
ceeding 22° C. (72° F.), or for a few hours at a temperature 
above 26° C. (79° F.), these bacteria will grow much more 
luxuriantly than in unheated milk, since in the latter the 
excessive number of lactic acid bacteria will hinder the develop- 
ment of other forms. 

Klimmer 251 states that peptonizing bacteria are usually in- 
troduced into milk with dirt (dried fasces). They are among 
the chief causes of summer diarrhoea of infants. 

Duclaux 23 ° calls attention to the fact that peptones are the 
normal product of digestion, and that countless millions of 
peptonizing bacteria are normally present in the intestines. 
Therefore it would seem questionable whether the addition of 
a few more would make any material difference. He thinks 
that the harm resulting from their presence has probably been 
overrated. 

Weber 182 has made a very thorough study of the effect of 
sterilization on the bacterial content of milk. He emphasizes 
the antagonism between the lactic acid and the peptonizing 
bacteria, and points to a possible danger from the use of 
the sterilized product. His conclusions are as follows : 



206 THE ARTIFICIAL FEEDING OF INFANTS. 

I. The methods of sterilization of milk in use at the present 
time are not sufficient to give ns with absolute certainty a germ- 
free milk. The so-called sterilized milk of the different dairies 
has a varying bacterial content. The higher the percentage 
of negative tests for bacteria the greater are the alterations 
brought about by the process which are already visible to the 
naked eye. 

II. The anaerobic bacteria play no considerable role in 
commercial sterilized milk, so far as these tests showed. 

III. Of the aerobic bacteria the thermophile are of no great 
practical importance, on account of their faculty of growing 
only at high temperatures. On the other hand, they may lead 
to errors in bacteriological investigations, since milk decom- 
posed by them will, when tested by culture experiments, seem 
apparently germ-free. 

IV. The aerobic bacteria isolated from sterilized milk all 
have the property of peptonizing casein. 

V. Apart from the group of thermophiles we can distinguish 
three groups of aerobic peptonizing bacteria, namely, — 

(a) Bacteria which decompose the milk rapidly within from twenty- 
four to forty-eight hours. Most of them grow well at room temperature. 
Most of them peptonize the casein without attacking the milk-sugar ; but 
some are also capable of breaking up the lactose with the formation of 
strong acid. 

(b) Bacteria which under the most favorable conditions decompose the 
milk only after five to seven days, usually when the reaction is weakly 
acid or amphoteric. Nearly all of them grow best at high temperatures, 
as well at 37° as at 50° C. One species grew well at 60° C. 

(c) Bacteria which do not alter the appearance of the milk, although 
they grow well. 

VI. A number of these peptonizing bacteria can cause putre- 
factive decomposition of cow's milk (sterilized) and form in 
this process sulphuretted hydrogen. Previous to its formation 
the casein must be peptonized. 

VII. Lactose serves to check putrefaction in milk in so far 



BACTERIOLOGY. 207 

as it favors the development of acid-producing bacilli which 
suppress the activity of the peptonizing bacteria. This peculi- 
arity of lactose is fully developed in raw milk. On the other 
hand, in milk which has been heated and so freed from the 
real acid-forming bacteria, this property is not in evidence or 
only to a very limited degree. Consequently in heated milk 
bacteria develop which are not found in raw milk, and which 
cause putrefactive decomposition of the milk. The use of 
so-called sterilized milk (commercial) for infant feeding would 
seem, then, to be not without danger, since the bacterial flora 
present in this product favor the occurrence of putrefactive 
changes. 

VIII. The so-called " toxic" peptonizing bacteria of Fliigge 
also occur in commercial sterilized milk, but not very frequently. 
Only three out of one hundred and fifty tests showed the pres- 
ence of these bacilli. Their mode of growth places them in 
the group of hay bacilli. They are remarkable for their ability 
to decompose albuminous substances and to form sulphuretted 
hydrogen. In this peptonizing power seems to lie the chief 
danger for the infant organism. 

Kalischer 204 experimented with one variety of pepto- 
nizing bacteria and found that they produced a soluble ferment 
capable of inverting cane-sugar but not milk-sugar. They did 
not attack the fat, and there was no evidence of diastatic 
fermentation. They form from casein, albumose, and later 
peptone, besides ammonia, volatile acids, leucin and tyrosin, 
aromatic oxy acids, and a mixture of bases. Indol, skatol, 
phenol, and cresol were not found. The ferments produced 
by these bacteria resemble very closely in their action lab and 
trypsin, except that the latter is not known to produce aro- 
matic oxy acids. 

Besides these main classes of bacteria, there are certain varie- 
ties which cause changes in milk the exact clinical significance 
of which is not thoroughly understood. Their presence ren- 



208 THE ARTIFICIAL FEEDING OF INFANTS. 

ders the use of such milk undesirable if not unsafe; fortu- 
nately, their presence can readily be detected. 

The bacillus cyanogenes or syncyanus, which is only active in 
acid milk, and the bacillus cyaneo-fluorescens of Zangemeister 
cause a blue color in milk. A red color is due to the presence 
of the micrococcus prodigiosus, the sarcina rosea, the bacillus 
lactis erythrogenes, and the saccharomyces rubra. A yellow 
color is due to the bacillus synxanthus. Mossier and Zundel 
have proved that the ingestion of such colored milk can set 
up a gastro-enteritis (Marfan). 

Certain micro-organisms have the property of rendering milk 
viscous. These are the micrococcus of Schmidt-Muhlheiin, the 
actinobacter (Duclaux), the bacillus lactis pituitosi (Lofner), 
the bacillus lactis viscosus (Adametz), the streptococcus Hol- 
landicus (Weigmann), the micrococcus of Freudenreich, the 
bacterium of Guillebeau, the bacterium Hessii, etc. 

Certain yeasts are also found, especially in milk which has 
undergone coagulation. Among these are the saccharomyces 
lactis, the saccharomyces rubra, and the penicillium glaucum. 105 

Maefax. 105 Of the various organisms described, the groups 
of lactic acid and peptonizing bacteria are most to be feared. 
They may do harm in one of two ways : either by their pres- 
ence in excessive numbers (this is more apt to occur during 
the summer months when conditions are favorable for their 
rapid multiplication) or through the products of their activity, 
such as butyric, lactic, propionic, and valeric acids, or leucin, 
tyrosin, ammoniacal compounds, and fatty acids. Among other 
toxic products which result from bacterial activity especial 
attention should be called to tyrotoxicon, isolated by Victor 
Vaughan, of Ann Arbor, from putrefied cream and cheese, and 
spasmotoxine, found by Brieger in putrefied milk. 

The Transmission of Infectious Diseases by Milk. 
Wyssokowitsch established the law that healthy glandular 
epithelium does not permit of the passage of microbes. Basch 



BACTERIOLOGY. 209 

and Weleniinsky, 105 in experimenting with pathogenic germs, 
have found that only those bacteria pass into the milk which 
give rise to hemorrhage or local disease of the mammary gland ; 
in other words, bacteria are not excreted by the mammary 
gland, but enter the milk only when the natural barriers are 
broken down by hemorrhagic or other necroses. 

Tuberculosis. 

It is certain that the milk of phthisical animals can cause 
tuberculosis in laboratory animals fed on it or inoculated with 
it under the skin or in the peritoneum. Tubercular disease 
of the udder or teat of the cow will almost certainly give 
rise to tubercular infection of the milk; when the disease is 
confined to other parts of the body, the milk of the animal 
may or may not contain tubercular virus. Bollinger, Xocard, 
and Galtier consider that the milk is certainly virulent only 
when the teat is affected by tuberculosis; on the other hand, 
Bang, Csokor, Ernst, Hirschberger, and Koubassoff have found 
the milk virulent even when the disease was limited to other 
parts of the body. All are agreed that the diagnosis of mam- 
mary tuberculosis in its early stages is very difficult. 105 

Clinical evidence has proved that milk from tubercular ani- 
mals can, and undoubtedly does, give rise to tubercular infec- 
tion through the gastro-intestinal tract; however, tuberculosis 
by ingestion is much less frequent than tuberculosis by in- 
halation. 

Holt believes that the danger of transmitting tubercular 
infection to infants by cow's milk is greatly exaggerated. 
Eecorded cases of such infection are extremely rare. In a 
series of one hundred and nineteen autopsies on tubercular 
patients, nearly all infants, he found no instance of it. Xorth- 
rup, in his large experience, came across but one undoubted 
case. 

H. Johxsox Collins 27 calls attention to the rarity of 
tubercular infection in infants from raw milk. The inves- 

14 



210 THE ARTIFICIAL FEEDING OF INFANTS. 

tigations of Gregari, Strauss, and Wurtz show that, so long 
as the gastric juice retains a normal degree of acidity, tuber- 
culosis of the alimentary canal is unlikely to occur. Kurlow 
and Wagner consider the gastric juice to be a strong bacteri- 
cidal agent. 

At a meeting of the Medical Society of the County of New 
York, January 29, 1900, 234 H. W. Conn, of Wesleyan Univer- 
sity, stated that it is still uncertain whether tuberculous pro- 
cesses in the cow which were localized in parts of the body 
other than the udder would lead to the appearance of tubercle 
bacilli in the milk of that animal. Of course this does not 
refer to general tuberculosis. From the fact that primary 
intestinal tuberculosis in man is rare, and because it is proba- 
ble that the organisms of human and of bovine tuberculosis 
are not identical, Conn thinks that there is good reason for 
believing that the danger of contracting tuberculosis from 
drinking milk has been greatly exaggerated. 

Koch, 261 at the recent meeting of the British Congress on 
Tuberculosis, July 23, 1901, emphasized that human and bovine 
tuberculosis were distinct forms of infection and could not be 
transmitted from one species to the other. He based these 
statements on animal experiments with human tubercle ba- 
cilli and on the rarity of primary intestinal tuberculosis in 
man. In the few positive cases in which this had occurred 
among thousands of autopsies he considered that it was im- 
possible to exclude accidental infection with the widely propa- 
gated bacilli of human tuberculosis. He believes, therefore, 
that the infection of human beings with bovine tuberculosis 
is of very rare occurrence. 

Whether the milk of a tubercular woman can affect the 
nursing infant is also a matter of dispute ; the conditions may 
fairly be considered analogous to those in the cow. Eoger and 
Gamier, in the Semaine Medicate, February 23, 1900 (abstract 
in the Philadelphia Medical Journal, June 23, 1900), report 
a case in which tubercle bacilli were isolated from the milk 



BACTERIOLOGY. 211 

of a woman suffering from pharyngeal and pulmonary tuber- 
culosis. The milk, when injected into a guinea-pig, caused 
death in thirty-three days, with typical generalized lesions. 

While the milk of a tubercular animal may contain no tuber- 
cle bacilli, it is possible that the toxins elaborated by them 
may be present and constitute a source of danger to the infant 
using such milk. 

As milk furnishes a good culture medium for most varieties 
of bacteria, its accidental infection with the germs of any of 
the infectious diseases, such as cholera, typhoid fever, diph- 
theria, etc., will render such a milk unfit for use. 

Diseased conditions of the cow, such as aphthous fever, in- 
fectious mammitis, anthrax, etc., or, in the woman, pneumonia, 
typhoid fever, scarlet fever, etc., will also constitute a contra- 
indication to the use of their milk 105 (see page 169, Bendix). 

It seems hardly necessary to enumerate all the other micro- 
organisms which have been found in milk. Owing to the lack 
of uniformity among different observers in their methods of 
study and in their descriptions of bacteria, it seems probable 
that numerous duplicates of the same species have been de- 
scribed as distinct entities (Conn). For the purposes of infant 
feeding it is not necessary to consider more than the three 
main groups, — namely, the lactic acid group, the proteolytic 
or peptonizing group, and what may be called the pathogenic 
group. According to Escherich, the bacillus coli communis 
can be included among the first, since it possesses the power 
of splitting up lactose into lactic acid. 

The role played by bacteria in the gastro-intestinal tract 
remains to be briefly discussed. Investigations to determine 
the relation which bacterial activity bears to the digestive pro- 
cesses give us, at best, unsatisfactory results, since it is mani- 
festly impossible to reproduce the conditions which obtain in 
the intestines of the living organism. 

Biedeet 7 considers that intestinal putrefaction is held in 
check principally by: 



212 THE ARTIFICIAL FEEDING OF INFANTS. 

I. Free hydrochloric acid, which is at its maximum in 
breast-fed children in the intervals between feedings (Langer- 
mann) . 

II. Lactic acid, which prevents the other forms of fermenta- 
tion in the stomach and small intestines (Biedert, Escherich, 
Richet) . 

III. Fat and fatty acids in the large intestines. 

IV. The absorption at the right time of the water and al- 
buminoid constituents of the food, thus leaving the lower 
intestine poor in these materials, and preventing the excessive 
growth of bacteria until the whole is excreted with the faeces. 
Gilbert and Dominichi came to the same conclusions (Dis- 
cussions of the Biological Society, Paris, 1894). They found 
fewest microbes in the duodenum ; from that point their num- 
ber increased until it was greatest at the ileo-caecal valve, to 
decrease towards the rectum and anus. 

Escherich (Deutsch. Med. Woch., October 6, 1898) empha- 
sizes the antiseptic action of lactic acid fermentation, and draws 
attention to the fact that the gastric juice of infants fed on 
cow's milk is a poor disinfectant, since so little free hydro- 
chloric acid is present. 

Biedert 7 finds that the bacteria chiefly concerned in fer- 
mentative processes are : 

I. The bacillus lactis aerogenes, which predominates in the 
upper part of the small intestine. It splits up lactose into 
lactic acid, carbon dioxide, and water, and thus ferments the 
chyme. By the production of acid it maintains an acid medium 
or reaction. 

II. The bacillus coli communis, which predominates in the 
lower intestine. It may flourish in either acid or alkaline 
media, and is capable of forming acid out of lactose. It is able 
to split up neutral fats into fatty acids, which it does chiefly 
in the large intestine. 

The latter is the predominating germ of the faeces. Other 
forms are also found, such as the hay bacillus, the tetracoccus, 



BACTERIOLOGY. 213 

the white and red hay bacillus, the capsulated hay bacillus, 
numerous cocci, etc. 

Escherich. 48 The bacillus lactis aerogenes owes its predomi- 
nance in the small intestine to the lactic acid which it produces, 
in connection with its power to live on the products of the 
decomposition of sugar in the absence of oxygen. Not until 
the sugar is exhausted in the colon is the field free for other 
bacteria. First, the bacillus coli communis, which lives on rem- 
nants of sugar and albumin and busies itself in splitting up 
fats. It is also an agent of putrefaction, acting on the casein 
residues, which are often considerable in artificially fed chil- 
dren. Where the bacillus lactis aerogenes gives way to the 
bacillus coli communis at the end of the ileum, we find that 
the intense acid reaction becomes weaker and yields to an 
alkaline reaction, due to the greater activity of the intestinal 
and pancreatic secretions. At this point the protection which 
lactic acid had given to the casein ceases (Schlichter). The 
acid reaction, especially in the case of breast-fed children, 
persists until near the end of the small intestine (Biedert, 
Heubner) . 

The breast-fed child leaves only a small casein remnant, but 
a relatively greater sugar and lactic acid remnant. Out of 
the (comparatively) large fat remnant the bacillus coli com- 
munis forms fatty acids in considerable quantity, thus pro- 
longing the acid reaction. When the infant is artificially fed, 
casein with its lime salts and its other alkaline products is 
apt to be conspicuous in the food residue. Its presence checks 
acid fermentation. 

Bacteria undoubtedly serve the purpose of helping to dis- 
integrate food-stuffs, especially those of tenacious vegetable 
fibre (von Hoffmeister in ISTeumeister's " Text-Book of Physio- 
logical Chemistry," vol. i., 1893-1895). This action may be 
a harmless one or may result in the formation of noxious 
products. When the infant is healthy, the intestine is emptied 
before any marked production of toxins occurs. 



214 THE ARTIFICIAL FEEDING OF INFANTS. 

Schloss:maxx 136 has conducted a series of experiments on 
the starch-decomposing properties of certain bacteria. He 
used pure cultures of the bacillus lactis aerogenes and the 
bacillus coli communis, and found that relatively high per- 
centages of starch were decomposed without the production of 
sugar. He concludes, therefore, that it is probable that a 
greater or less proportion of the starch in an infant's diet 
cannot be utilized for the needs of the organism. Since the con- 
ditions of the experiment can hardly be said to reproduce those 
which obtain in the gastro-intestinal tract of the infant, it would 
seem that his conclusions cannot possess much clinical value. 

Biedert draws attention to the fact that the addition of 
starch and lactose to the infant's diet favors the production 
of an acid reaction. Baginsky and Moro have also found that 
the bacillus coli communis and the bacillus lactis aerogenes 
can decompose starch without the production of sugar. 

Escherich has proved that different forms of bacteria can 
split up sugar. As gas is produced, which passes off with the 
faeces, he thinks that a portion of the sugar would thereby 
be lost for the needs of the organism. 

Hammarsten calls attention to the fact that, besides the 
action of enzymes in the intestinal tract, we have to take into 
consideration fermentative and putrefactive changes due to 
the action of bacteria. These are less intense in the upper 
bowel, increase as we descend to the ileo-caecal valve, and then 
diminish in the large intestine, sigmoid flexure, and rectum. 

So long as the intestinal reaction is strongly acid, fermen- 
tation occurs, but not putrefaction. Gamgee asserts that the 
amount of acid formed by the organized ferments is so great 
that the intestinal content, from the pylorus to the caecum, is 
always acid in reaction. 

Intoxications through Milk. 
Soxxexberger 205 lays stress on the possibility of intoxica- 
tion by plant alkaloids which have gained entrance into the 



BACTERIOLOGY. 215 

milk from the fodder. Biedert, Meinert, Gaertner, Alt, and 
Scholl have also testified their belief that enteric diseases in 
the infant can have their origin in intoxications from this 
source. Scholl emphasizes the importance of careful inspection 
of the fodder, since the alkaloids and toxins contained in the 
milk of cattle fed on these poisonous weeds cannot be purified 
with certainty by the Soxhlet process. 

We know that the mammary gland, besides its other proper- 
ties, possesses that of eliminating poisons; this has recently 
been demonstrated conclusively by Frohner (Mojiatsheft fiir 
Prakt. Heilhunde, Bd. ii.). Schneidemiihl, in his "Text- 
Book of Comparative Pathology," vol. ii., 1896, makes this 
statement regarding the excretion of poisons by the mammary 
gland : " Milch-cows have a greater power of resistance against 
poisonous substances than other animals, because the height- 
ened activity of the mammary gland brings about a more rapid 
and complete elimination of the poison (which has found en- 
trance) than in other animals." 

The source of these poisons is to be found in the plant alka- 
loids; even in minute amounts their ingestion in milk may 
give rise to serious symptoms, although the cattle which have 
fed on the plants containing them show no symptoms of poi- 
soning. The poisonous weeds are most often found in clover 
fields; among them are colchicum, digitalin, hyoscyamus, 
papaver somniferum, conium maculatum, hellebore, euphorbia, 
sinapis, etc. 



CHAPTER IX. 
STERILIZATION AND PASTEURIZATION. 

Most authorities are agreed as to the advisability of the use 
of heat in preparing milk for an infant's meal, differing only 
in their choice of the degree to be employed. On the other 
hand, it is well recognized that the ideal to be always sought 
for is milk obtained and handled with such strict precautions 
as to be nearly sterile and kept free from contamination until 
administered. Such a milk does not require any process of 
heating for the destruction of germs, but unfortunately its 
production is limited in amount and necessitates such expense 
as to place it beyond the reach of all but a favored few. In 
preparing food for the majority of infants, at least during the 
summer months, we will have to employ some degree of heat. 

Jacobi 76 says that " as long as cows are tubercular, and 
milk is exposed to contagion from scarlet fever, diphtheria, 
typhoid fever, etc., as ordinarily obtained it needs to be boiled/' 
H. J. Campbell, 29 however, calls attention to the fact that 
foul milk cannot be rendered safe by any amount of boiling 
or by other methods, apropos of which is the report by Mar- 
fan 105 of an epidemic of severe gastro-enteritis in children 
fed on sterilized cow's milk. The milk was sixteen hours old 
when sterilized, allowing sufficient time for the development 
of toxic substances which are not affected by sterilization. 

Jemma, 236 in the Rev. Mens, des Mai. de YEnfance, vol. 
xviii., No. II., reports the results of his studies on the milk 
of tubercular animals. He found that young rabbits fed on 
sterilized milk containing dead tubercle bacilli died within 
from fifteen to twenty days of advanced cachexia or later of 
marasmus. Other cases fed on plain sterilized milk or on 
their mother's milk nourished. The autopsies showed only 
216 



STERILIZATION AND PASTEURIZATION. 217 

enteritis and fatty degeneration of the liver. It is therefore 
erroneous to believe that boiling or sterilization obviates the 
dangers of using milk from tubercular animals. 

Failures in infant feeding will continue to occur, even when 
the milk administered is absolutely sterile, for, as Welling- 
ton Stewart 126 has pointed out, such a milk becomes alive 
with micro-organisms a few minutes after its ingestion. No 
one will deny, however, that the healthy infant can more suc- 
cessfully digest a pure milk than one contaminated with germs, 
many of which may be entirely foreign and harmful to a 
marked degree. 

Methods of heating Milk. 
Three methods are recommended, — namely, pasteurization, 
sterilization, and boiling. Great confusion exists in the use 
of the term " sterilization." As will be seen, complete sterili- 
zation cannot be obtained at 100° C. in less than from one 
and a half to two hours. Unless the method employed is accu- 
rately described, however, it is impossible to decide whether 
such a complete process or its equivalent has been carried out. 
As a general rule, the term seems to be applied to any process 
which carries the temperature to or above 100° C. for a certain 
time in some sort of an apparatus. This may or may not 
secure the absolute destruction of all germs, but for purposes 
of discussion the terms pasteurization, sterilization, and boil- 
ing may be accepted as defined below. 

Pasteurization. 

This method has taken its name from part of a process 
which Pasteur recommended very successfully for the preserva- 
tion of wine and beer. 

To R. G. Freeman, of New York, the credit belongs of 
having drawn the attention of the profession in this country 
to pasteurization, and of devising an apparatus for the prepa- 
ration of milk in this way. He recommends that milk should 



218 THE ARTIFICIAL FEEDING OF INFANTS. 

be heated to a temperature of 68° C. (155° F.) for thirty 
minutes. This destroys most of the bacteria, including those 
of tuberculosis, typhoid fever, and diphtheria, and causes 
practically no chemical change in the milk, not even altering 
its taste. 

Holt defines pasteurization as that method by which the 
temperature is raised to, and maintained at, 75° C. (167° F.) 
for twenty minutes. This destroys the bacilli of cholera, 
typhoid, diphtheria, and tuberculosis, the bacillus coli com- 
munis, and ordinary pathogenic germs. It does not destroy 
spores, and milk so prepared will keep for two or three days 
at room temperature. It does not alter the taste; moreover, 
the character and digestibility of the curd are not affected. 
Whether there are any changes in the nutritive value of the 
milk is a point not yet settled. Holt believes that pasteuriza- 
tion is sufficient for ordinary purposes, but that in cities during 
very hot weather, when ice is scarce and milk highly con- 
taminated, sterilization is imperative. 

Cautley 38 considers that pasteurization at from 70° to 
75° C. (158° to 167° F.) for thirty minutes, followed by rapid 
cooling in clean, well-stoppered bottles, is sufficient for all 
practical purposes. Such a milk should not be kept longer 
than from twelve to twenty-four hours. It is not seriously 
changed either chemically or in its taste; therefore he recom- 
mends it as a general rule. 

Freeman. 55 - 56 - 157 Pasteurized milk was distributed during 
a period of three years to the poor of New York City in the 
summer months. Eoutine dilutions were used : in some, milk 
and water in equal parts plus lactose and lime-water ; in others, 
milk and barley-water equal parts plus cane-sugar. During 
the three years of its use the number of deaths from diarrhceal 
diseases was less by eight hundred and sixty than in the three 
preceding years. Over one million bottles were given out 
during this time. 

F. Siegert, of Strasburg, calls attention to the fact that, 



STERILIZATION AND PASTEURIZATION. 219 

since the year 1893, Forster, of Amsterdam, had employed 
pasteurization at 65° C. (150° F.) for fifteen minutes, and had 
found the results satisfactory in freeing the milk from patho- 
genic germs. Siegert carried out the same method in Stras- 
burg on a large scale with good results. 

Leeds 93 draws attention to the practical sufficiency of pas- 
teurization as regards the destruction of pathogenic germs, 
and is in favor of carrying out the process immediately after 
milking. The advantages claimed for this method are that 
the temperature of the milk need be raised only from 98.4° F. 
(blood-heat) to 157° F. (instead of from 40° to 50° F., the 
usual temperature at which milk is kept). This saves expense 
and prevents the development of bacteria and the production 
of toxins. 

Monti advises to heat milk to 60° C. (140° F.) for ten 
minutes, then to cool to 6° or 8° C. (42.8° or 46.4° F.). The 
milk should be kept at this temperature until used. This 
process kills most of the germs and prevents sporulation with- 
out alteration of the milk constituents. 

Bavenel 260 gives Sternberg's table of the thermal death- 
point of some of the most important bacteria. 

Bacillus diphtheria? 58° C. (136° F. ) for ten minutes 

Typhoid bacillus 56° C. (133° P\) for ten minutes 

Pneumococcus 52° C. (125° P.) for ten minutes 

Bacillus coli communis . 60° C. (140° P.) for ten minutes 

Bacillus acidi lactici 56° C. (133° P.) for ten minutes 

Staphylococcus pyogenes 

aureus 58° C. (136° F. ) for ten minutes 

Staphylococcus pyogenes 

albus 62° C. (144° P. ) for ten minutes 

Bang, of Copenhagen, 259 found that a temperature of 60° C. 
(140° F.) for fifteen minutes was sufficient to destroy all the 
tubercle bacilli in milk, so as to prevent infection when they 



220 THE ARTIFICIAL FEEDING OF INFANTS. 

were injected into the peritoneal cavity; this degree of heat 
was sufficient to weaken the bacilli so that after pasteurization 
for two minutes they were incapable of infecting through the 
alimentary canal. In another series of experiments higher 
temperatures— 70° C. (158° F.>, 75° C. (167° P.), and 80° C. 
(176° F.) — were applied to milk from tuberculous udders, 
but sometimes failed to destroy the tubercle bacilli. Since the 
milk was heated in open bottles, the failure to destroy the 
germs was ascribed to the uneven application of the heat to 
the pellicle and to the foam on the surface of the milk. 

Theobald Smith 255 had previously discovered from ex- 
periments with pure cultures of tubercle bacilli in different 
media that a temperature of 60° C. (140° F.) for fifteen min- 
utes was sufficient to destroy all the bacilli, and that most of 
the germs were destroyed within from five to ten minutes. 
He did not obtain equally good results with tubercle bacilli 
in milk, and considered that this was due to the protection 
of the pellicle. H. L. Eussell, of Wisconsin University, obtained 
similar results. He found that heating to 60° C. in closed 
bottles destroyed the tubercle bacilli in ten minutes. 

Forster 260 gives the thermal death-point of the tubercle 
bacillus as follows: 65° C. (150° F.) for thirty minutes, 
68° C. (155° F.) for fifteen minutes, 75° C. (167° F.) for 
ten minutes. 

Blackader. 207 Wroblewsky has called attention to the fact 
that certain of the calcium salts which are normally soluble 
are made to enter into insoluble combinations by high tem- 
peratures, while Duclaux has pointed out that the gastric 
ferments are effective only in the presence of minute quantities 
of calcium and other mineral salts, the mineral varying with 
the specific form of fermentation (see Conradi). If the cal- 
cium salts are rendered insoluble by heat, then the coagulation 
of casein will to that extent be arrested or delayed. In cor- 
roboration of this view we. know that boiled milk undergoes 
coagulation by rennet only with much difficulty. Since this 



STERILIZATION AND PASTEURIZATION. 221 

primary coagulation in the stomach appears to be necessary 
for the normal digestion of milk and its absorption into the 
system, it is certainly questionable whether, as a rule, boiled 
milk can be absorbed and assimilated as readily as milk which 
has not been brought to a temperature sufficient to change the 
condition of its calcium salts. On the other hand, this action 
may sometimes be of distinct advantage in those conditions 
of the infant's stomach in which the action of rennet, either 
directly or reinforced by the presence of fermenting bacteria, 
is so intense as to lead to the development of firm curds. 

Blackader thinks that unheated milk probably contains fer- 
ment-like bodies which, when absorbed, are of distinct value 
to the organism. Babcock and Eussell (Fourteenth Annual 
Eeport of the Wisconsin Experiment Station) discovered that 
milk obtained in a condition of perfect sterility undergoes self- 
digestion owing to the presence of a trypsin which is readily 
destroyed by heat. Blackader prefers to use always good un- 
heated milk. When this cannot be obtained, he employs a tem- 
perature of 60° C. (140° F.) for fifteen minutes. 

Conradi 240 found that the subjection of milk to tempera- 
tures of over 80° C. (176° F.) lowered the coagulation point 
of the milk in the presence of lime and similar salts from 8° 
to 12° C. ; on the other hand, postponing the process of lab- 
coagulation. These facts prove that temperatures of over 
80° C. cause a lasting chemical and physical alteration in the 
milk. 

Troitsky 141 > 142 considers it established that ordinary lactic 
acid ferments and pathogenic bacteria encountered in milk, in- 
cluding tubercle bacilli, are destroyed by a temperature of 80° 
C. (176° F.) for ten minutes or 68° C. (155° F.) for thirty 
minutes. The casein ferments resist heat much better. The 
bacillus subtilis, tyrothrix tenuis, and bacillus mesentericus 
vulgatus produce spores which are only destroyed at very high 
temperatures. If the adult germ succumbs at about 100° C, 
its spores can resist a temperature of 115° C. for one minute. 



222 THE ARTIFICIAL FEEDING OF INFANTS. 

Jacobi 19 thinks that for the purpose of pasteurization " milk 
should be subjected to a temperature of from 65° to 68° C. 
(150° to 155° F.) for twenty minutes, but that it may be wise 
to extend the process over a longer time." 

Johannessen 20S > 230 thinks that with proper precautions as 
to the feeding of cows, etc., we may hope to obtain milk which 
is primarily free from germs. Under the present conditions 
milk must be pasteurized and then kept cool (below 18° C), 
and administered within twelve hours. Heating to 70° C. 
for some time destroys pathogenic germs without altering to 
any extent the chemical composition of the milk. 

Von Starck 148 > 150 believes in the efficacy of pasteurization 
to destroy pathogenic germs. 

Getty 68 had milk pasteurized at 75° C. (167° F.) for 
twenty minutes put in separate sterile bottles plugged with 
sterile cotton, cooled immediately and kept on ice. This was 
distributed during June, July, August, and September to a 
large number of children at Yonkers, New York. He asserts 
that a reduction of seventeen per cent, in the total mortality 
was effected during the two years of its use, and that the num- 
ber of deaths from digestive disturbances was reduced almost 
one-half. 

Huppe 133 believes that milk is best treated from a physio- 
logical stand-point by the application of heat under 75° C, 
since greater temperatures produce chemical changes. 

H. Johnstone Campbell 29 thinks that pasteurization pre- 
sents fewer disadvantages than sterilization ; hence it is gener- 
ally to be preferred. 

J. Lewis Smith 129 thinks that pasteurization should always 
be recommended and never a higher temperature. 

Campbell 219 suggests a cheap method for home pasteuriza- 
tion. The necessary articles are (a) a jar, the cork of which 
is perforated for (b) a chemical thermometer, and (c) sterile 
non-absorbent cotton. The jar is filled with the milk to be 
pasteurized, the cork, with the thermometer in place, inserted, 



STERILIZATION AND PASTEURIZATION. 223 

and the whole placed in a saucepan of water and heated until 
the temperature of the milk reaches 160° F. The sauce- 
pan is then set at the back of the stove for twenty minutes. 
The cork is next replaced by a cotton plug, and the milk is 
ready for use or to be cooled and kept until wanted. The 
whole outfit can be obtained at the cost of about one dollar. 

Caestaiks Douglass, in the Glasgow Medical Journal, 220 
suggests that the unpleasant taste of boiled milk is in large 
part due to the film which forms on the sides of the vessel 
above the bubbling fluid. As the fluid subsides, this film 
becomes overheated and charred and is carried back into the 
milk at its next ebullition. In proof of this he has noted that 
if milk is boiled in a flask and constantly agitated, the altera- 
tion in taste is much less. Douglass firmly believes in some 
vital property of fresh milk which a temperature of 100° C. 
destroys; hence he prefers pasteurization. 

Objections to Pasteurization. 

Marfan 103 objects that pasteurization requires complicated 
apparatus and the milk must be cooled rapidly afterwards. It 
keeps good for a short time only, and one is never sure that 
all the lactic ferments have been destroyed; therefore he does 
not recommend it. 

Comby 62 considers that pasteurization is useful to preserve 
the milk, but that all the pathogenic germs are not destroyed. 

Biedert 7 asserts that the lactic acid bacilli are destroyed by 
pasteurization, while the proteus and the coli groups are not 
affected. He recommends this method only for institutions 
in which the danger of milk contamination is minimized. 

Koplik. 80 ' 81 Pasteurization destroys the pathogenic germs 
of most known diseases, but it does not destroy the milk bac- 
teria, which are much more frequently the cause of trouble. 
Most of these fall under three groups : A. Those which form 
lactic acid. B. Those which form butyric acid. C. Pepto- 
nizing bacteria. Groups B and C are not affected by any 



224 THE ARTIFICIAL FEEDING OF INFANTS. 

temperature at or below 100° C, although cold inhibits their 
growth. Heating to from 90° to 92° C. destroys Group A. 
Since Groups B and C are not destroyed by pasteurization, 
he considers milk so prepared an uncertain and at times a 
dangerous food. He therefore advises sterilization for ten 
minutes at either 90° or 100° C. He has observed various 
forms of " milk infection" in infants fed on pasteurized milk. 

Sterilization. 

Marfan. 119 Miquel found that all germs are killed at the 
end of one hour by heating to 105° C, at the end of half an 
hour by a temperature of 107° or 108° C, and at the end 
of fifteen minutes by a temperature of 110° C. Troitsky 
states that sterilization is complete only after exposure to 
100° C. for from one and a half to two hours, or even longer. 
Complete sterilization of milk, therefore, can only be accom- 
plished by heating it to 100° C. for from one and a half to 
two hours, to 105° C. for one hour, to 107° or 108° C. for 
half an hour, or to 110° C. for fifteen minutes. (Higher de- 
grees of temperature, daily sterilization at 100° C. for thirty 
minutes during three days, so-called fractional sterilization 
or Tyndallization, or heating in a special apparatus (auto- 
clave) where the pressure can also be raised, would all serve 
the same purpose, but practically these methods are not in 
use. — Editors. ) 

To Soxhlet, as Jacobi well says, belongs the immortal merit 
of having systematized and popularized the method of boiling 
and thereby sterilizing milk in single portions for the use of 
infants. Marfan believes that milk heated in a double boiler, 
such as the Soxhlet apparatus, to 100° C. for forty minutes 
will remain sterile from four to five days if the conditions 
are favorable. If this is used within twenty-four hours, it 
may be considered practically sterile. The same physical and 
chemical changes are found in this milk which are found in 
any milk heated to or above 80° C. If rubber corks are used, 



STERILIZATION AND PASTEURIZATION. 225 

as in the Soxhlet apparatus, a disagreeable odor and taste may 
be imparted to the milk. Marian's experiments show that the 
actual temperature of the milk never exceeds from 95° to 
96° C.,* so that the casein ferments cannot be destroyed. 
(The slow development of the latter may be explained by the 
hermetic closure of the jars, which excludes all oxygen. — 
Editors.) 

It is probable that the effect of a high temperature which 
alters the mode of coagulation of (sterilized) milk is favor- 
able rather than unfavorable to its digestion. The only satis- 
factory test would be to feed a series of infants of like age and 
weight on sterilized milk and raw milk, the amounts of food 
being carefully estimated; in other words, to carry out metab- 
olism experiments. The results of test-tube experiments are 
too unlike the actual conditions to be satisfactory. Marfan's 
practical experience leads him to the following conclusions: 
with good methods of purification by heat, accidents of feeding 
are much reduced in number, gain in weight is much more 
steady, and gastro-enteritis, especially in its severe forms, 
becomes less frequent. 

Budin, in 1892, found that pure cow's milk, if sterilized, 
could be digested by the new-born infant. Since then this 
view has been corroborated by Chavanne, Variot, Comby, B. 
Lazard, Drapier, and Madame Bres (1896). 

Marfan states that the avoidance of excessively high tem- 
peratures, the exclusion of air, and rapid after-cooling have 
served to diminish the changes brought about by sterilization, 
which are found only to a slight degree in the ordinary com- 
mercial sterilized milk sold in France. It is important that 
thte milk should be used within a week, otherwise the fat- 
droplets will separate. Heating to 40° C. and a thorough 
shaking will restore the emulsion. Estimates made by the 
pharmacist of the Hopital des Enfants Malades show that the 

* Johannessen 230 says that the temperature of the milk in the bottles of 
the Soxhlet apparatus rarely exceeds 96° C. 

15 



226 THE ARTIFICIAL FEEDING OF INFANTS. 

percentage of phosphoric acid in sterilized milk is practically 
always normal, provided the bottle is first thoroughly shaken. 
If the bottle is not disturbed, a layer of mucus is formed on 
the sides and bottom, containing from one-half to one-thirtieth 
of the total phosphoric acid present. Marfan does not consider 
that these facts constitute valid objections to the use of steril- 
ized milk. 

Biedert 7 approves of sterilization. The objection raised, 
that lactic acid bacteria are destroyed by this process, does 
not hold, since many of these organisms are already present 
in the mouth and stomach. The milk mixture should be put 
into separate bottles, sterilized, immediately cooled, and kept 
cool until ready for use. Since the majority of people are 
unable to carry out this process, simple boiling in a covered 
receptacle can be recommended, provided the milk is not after- 
wards disturbed. 

Fliigge has objected that the fat separates in large globules 
after sterilization. This can be remedied by shaking the bot- 
tles in a circular direction before use. 

Fenwick 52 recommends sterilization when milk is liable 
to be contaminated; otherwise pasteurization is preferable. 

Thomson - 147 advises sterilization for those who live in cities, 
as long as dairy methods are so imperfect. The milk must be 
sterilized while fresh. Pasteurization is not wholly satis- 
factory. 

Comby 62 considers it indispensable to boil or sterilize cow's 
milk for young infants, especially in cities, owing to the dan- 
gers of tuberculosis, aphthous fever, etc. He permits the use 
of pure milk only in exceptional cases, as in the country dis- 
tricts or where the cows react negatively to tuberculin. Sterili- 
zation prevents germ infection and causes molecular modifica- 
tion of the casein which renders it more assimilable for young 
infants. 

Variot 151 believes the best method is to have the milk ster- 
ilized in gross at 115° C. at the dairy farms immediately after 



STERILIZATION AND PASTEURIZATION. 227 

milking. It is then hermetically sealed in quarter- and half- 
litre bottles. These are distributed with careful directions as 
to the size of the meals. He usually gives whole milk after one 
month ; to those with weak digestion he gives it after the second 
or third month. Before that time milk should be diluted with 
from one-third to one-fourth its amount of water. Most of 
his cases so treated (eight hundred in all) did well. Scurvy 
was never observed and rickets but seldom; many of the 
infants, however, were constipated and anaemic. 

Baginsky 6 thinks that the Soxhlet method gives the best 
practical results, although it does not completely sterilize the 
milk. Immediate cooling and use within two days are essen- 
tial factors. Many children cannot digest milk so treated, 
however. He has never encountered scurvy following its use. 

Troitsky. 141 ' 142 Sterilization probably produces some 
chemical changes in milk, but does not render it indigestible. 
Under present conditions we have no better substitute for 
mother's milk. Both sterilized and raw milk are good culture 
media, but germs grow less readily in the former. The bottle 
of sterilized milk may be opened once or twice without be- 
coming infected, but each repetition increases the danger of 
contamination. 

Koplik. 80 ' 81 Years of observation have not borne out the 
objection that milk is rendered more difficult of digestion by 
sterilization. 

Starr. 133 Sterilized milk is especially useful on a long 
journey during the heated term and as a temporary change 
of diet for delicate children suffering . from gastro-intestinal 
diseases. 

Ashby and Wright 2 think that it is impossible to sterilize 
stale milk at the home. If the milk is fresh and clean, a 
temperature of from 70° to 75° C. is sufficient; otherwise 
it should be heated to 100° C. for half an hour. 

F. G-ERNSHEIM. 67 Variations in the fat content of the sepa- 
rate bottles can be avoided only by thorough stirring and 



228 THE ARTIFICIAL FEEDING OF INFANTS. 

shaking of the milk just before filling. If the milk is kept in 
a large vessel, it must be well stirred in a circular direction 
before pouring. Contamination with germs is not likely to 
occur if the bottles have previously been sterilized. 

Objections to Sterilization. 

Carstexs, of Leipsic, at the seventieth meeting of the So- 
ciety of German Naturalists and Physicians, in 1898, empha- 
sized the importance of cleanliness in securing and handling 
milk, and the disadvantages following the use of sterilized 
milk (anaemia, rickets, and scurvy). If milk can be obtained 
clean and fresh, simple boiling for ten minutes is preferable 
to sterilization; otherwise, we sterilize for thirty minutes. 
The administration of sterilized milk exclusively beyond the 
ninth or tenth month is not to be recommended. He believes 
that a dilution of one to three is necessary only for small 
babies during the first month; after the second month we can 
use stronger concentrations. 

Von Starck, of Kiel, 150 expresses these views : 1. The pro- 
longed and exclusive use of sterilized milk for infants leads 
in a considerable number of cases to disturbance of nutrition, 
showing itself as severe anaemia, rickets, scurvy, etc. 2. The 
uniformity of the diet is largely responsible for this, besides 
the physical and chemical changes produced by sterilization. 
3. If clean raw milk cannot be obtained, the milk should be 
heated, to what degree and for how long depends on the 
circumstances of the individual case. 4. In certain condi- 
tions sterilization is necessary. 5. Fresh, clean boiled milk 
is the normal substitute for mother's milk, and gives as good 
results as sterilized milk without the disadvantages of the 
latter. 

Eighty-four out of three hundred physicians in Schleswig- 
Holstein reported the occurrence of rickets, anaemia, retarded 
development, constipation, etc., resulting from the continued 
use of sterilized milk. 



STERILIZATION AND PASTEURIZATION. 229 

Dawson Williams, Bendix, Czerny, and von Stark, of 
Munich, believe that scurvy may result from the continued use 
of sterilized milk, and in 1895 Starr reported five cases of 
this disease in infants under two years, following its employ- 
ment. 

Holt says that infants fed on sterilized milk are apt to be 
constipated. 

AEoxti " is convinced that the value of milk as an infant 
food is distinctly affected by sterilization, and that many dis- 
advantages are connected with its use in infant feeding. 
Bickets, dyspepsia, and high-grade anaemias are apt to result. 

J. Kixgstox Bartox 15 thinks that scurvy will undoubtedly 
follow the use of completely sterilized milk, if no fresh food 
is administered at the same time. 

H. Johxstoxe Campbell. 29 Scurvy and rickets often fol- 
low the use of sterilized milk. Since it is not well digested, 
the infant receives an insufficiency of food, especially of the 
fats and carbohydrates. 

The American Pediatric Society has collected a total of 
three hundred and fifty-six cases of scurvy. 3 Out of this num- 
ber, sixty-eight cases were fed solely on sterilized milk. 

Jacobi 70 calls attention to the fact that, unless sterilization 
be complete, the resistant spores of bacteria may find a better 
opportunity for development, since the lactic acid ferments 
have been destroyed. The longer such milk is kept before it 
reaches the consumer the more dangerous it becomes. Cream 
separates from sterilized milk. Benk found that this separa- 
tion occurs to a slight extent within one week of sterilization, 
and that later 43.5 per cent, of the cream was separated. 
Jacobi considers the question of chemical changes not jet 
definitely settled. The substitution of sterilized milk for 
mothers milk as the sole food for the infant is a mistake. 
Digestive disturbances and rickets are frequently due to its 
persistent use, and it appears to be, at least occasionally, a 
co-operative cause of scurvy. 



230 THE ARTIFICIAL FEEDING OF INFANTS. 

We have found it convenient to place in tabulated form a 
list of the physical and chemical changes which are said to 
follow the process of sterilization. 

A. Decomposition of lecithin and nuclein (Baginsky, von 
Starek, Biedert, Jacobi, Edlefsen), also of nucleoli (Edlef- 
sen). 

B. Organic phosphorus is diminished and inorganic phos- 
phorus increased in amount (Baginsky, 1894). 

C. The greater part of the phosphates are rendered insolu- 
ble (Monti, Dawson Williams, H. Johnstone Campbell). 

D. Precipitation of the calcium and magnesium salts (Ashby 
and Wright, Jacobi, Dawson Williams, H. Johnstone Camp- 
bell). 

E. The greater part of the carbon dioxide is driven off 
(Johannessen, Dawson Williams, H. Johnstone Campbell). 

F. Normal lactic acid fermentation is prevented (Biedert). 

G. Lactose is completely destroyed (Leeds, Baginsky). Du- 
claux denies this. Johannessen states that it does not occur 
below 110° C. 

H. " Caramelization" of certain portions of the lactose 
(Holt, Eenk, Monti, Jacobi, Carpenter). 

I. The fat emulsion is partially destroyed or rendered im- 
perfect by the coalescence of the fat-globules (Eenk, Biedert, 
Monti, Ashby and Wright, Jacobi, J. Lewis Smith, H. John- 
stone Campbell, Johannessen). 

J. Separation of the serum-albumin begins at 75° C. and 
increases as the temperature is raised (Benk, Koplik, Cautley, 
Jacobi, Freeman, J. Lewis Smith, H. Johnstone Campbell). 

K. Casein is rendered less easy of coagulation by rennet 
(Baginsky, Leeds, Holt, Koplik, J. Lewis Smith, H. Johnstone 
Campbell ) . 

L. Casein is slowly and imperfectly acted upon by pepsin 
and pancreatin (Leeds, Holt, Jacobi, H. Johnstone Campbell). 
Leeds says that the proteid substances become attached to the 



STERILIZATION AND PASTEURIZATION. 231 

fat-globules and probably hinder to some extent fat assimi- 
lation. 

M. Peptones and toxins can be found after prolonged ster- 
ilization (von Starck). They are said to be produced by the 
action of chlorides on casein (A. Christiaens, U Union Phar- 
maceutique, August 15, 1894, cited by Marfan). 

N. The starch-liquefying ferment is destroyed and coagu- 
lated (Leeds, J. Lewis Smith). 

0. The taste is rendered objectionable (Kenk, Holt, Caut- 
ley, H. Johnstone Campbell). Marfan considers this a small 
objection, as the infant's taste is poorly developed. 

Boiling. 

Marfan. 105 Milk boils at about 101° C. It rises before 
boiling, beginning at 75° C, according to Comby, and 85° C, 
according to Gautrelet. It is necessary to break up the skim 
on the surface of the milk and to keep it on the fire until 
large bubbles appear. Milk boiled from three to four minutes 
does not contain lactic ferments or pathogenic germs, but it 
will not keep for any length of time, because the spores of the 
casein ferments are not destroyed. The skim is composed of 
casein, but, since the latter is present to excess in cow's milk, 
Marfan does not consider this objectionable. The increase in 
density to which Duclaux and Crolas have called attention 
is too insignificant to be of any consequence. If milk can be 
boiled directly after milking, and used the same day, it may 
be employed without hesitation. 

Jacobi 76 calls attention to the fact that pasteurization and 
sterilization are logical developments of his plan of boiling 
milk which he advocated forty years ago. He asserts that 
boiling expels air. The following bacteria are destroyed: the 
bacilli of typhoid fever, diphtheria, tuberculosis, cholera, the 
oi'dium lactis. Some varieties of proteus and most of the bacilli 
coli communis are rendered innocuous; the hay bacillus and 
the bacillus butyricus are not destroyed. Jacobi thinks that 



232 THE ARTIFICIAL FEEDING OF INFANTS. 

the daily home sterilization of milk is far preferable to the 
risky purchase from wholesale dealers who cannot guarantee, 
as they cannot know, the condition of their wares. 

Sommerfeld. 128 Fliigge advises for practical work to boil 
the milk for a short time (which destroys most of the patho- 
genic germs), then to cool it rapidly and protect it from air 
infection. Cooling hinders or checks the development of dan- 
gerous forms, such as the peptonizing and anaerobic bacteria, 
He thinks that Soxhlet's method requires too long boiling and 
does not lay sufficient stress on rapid cooling. Prolonged heat- 
ing causes physical and chemical changes in milk. 

Czerny 34 advises boiling for ten minutes. 

Henoch 71 advises that only pure milk should be used and 
that it should be boiled for half an hour. 

Bendix 10 disapproves of boiling for more than half an hour, 
since change of taste and other deleterious alterations may be 
produced. Milk so prepared should be used within from 
twenty-four to thirty-six hours at the longest. 

Objections to Boiling. 
At the Moscow Congress, in 1897, Schlossmann asserted 
that boiling milk caused alterations in the fat, albumins, and 
phosphorus-containing substances. 

Chemical Changes in Sterilized Milk. 

Holt. 69 The changes in milk resulting from the application 
of heat begin at 180° F. and become more marked the higher 
the temperature and the longer it is maintained. Sterilization 
should be done at the dairy. Its value consists in the preven- 
tion, not the cure, of disease; it is unnecessary if pure milk 
can be freshly obtained. 

Eichmond. 120 The most marked characteristic distinguish- 
ing sterilized from new milk is the state in which the albumin 
exists. In milk which has been heated, coagulation does not oc- 
cur ; but if it is acidified or saturated with magnesium sulphate, 



STERILIZATION AND PASTEURIZATION. 233 

the albumin separates with the casein. It appears to be changed 
from a soluble to a colloidal form. Not more than 0.1 per cent, 
of albumin is found in sterilized milk in a soluble form. 

Cream rises extremely slowly in sterilized milk ; in six hours 
only one-tenth of the amount is present that we should have 
found in raw milk. In twenty-four hours the bulk of the cream 
will rise, but the total quantity will be less than that from the 
same amount of raw milk, while the fat percentage will be 
forty as against thirty in fresh cream. 

Partial freezing of milk causes no changes in any of the con- 
stituents except the water. Vieth found that exposure of large 
quantities of milk to — 10° C. for three hours caused it to 
freeze, except in the centre. The ice consisted of two layers, 
one of cream and the other of skimmed milk. The cream con- 
tained 19.23 per cent, fat, 2.64 per cent, proteids, 3.33 per 
cent, lactose, and 0.52 per cent. ash. The milk contained 
0.68 per cent, fat, 2.80 per cent, proteids, 3.95 per cent, lac- 
tose, and 0.60 per cent. ash. The liquid portion contained 
5.17 per cent, fat, 5.38 per cent, proteids, 7.77 per cent, lac- 
tose, and 1.18 per cent. ash. These figures show that milk 
cannot be frozen in blocks, from which pieces can be cut off 
and melted for use, without its composition being modified to 
a serious extent. 

At 70° C. albumin undergoes change. It is not precipi- 
tated, but is converted into a form which is precipitated by 
acid magnesium sulphate and other precipitants of casein. 
Heating above 70° C. alters the taste and smell of milk. At 
about 80° C. certain organized principles, the nature of which 
is not fully known, undergo a change. When the tempera- 
ture nears 100° C, calcium citrate is deposited. By keep- 
ing at this temperature for some time, slight oxidation sets 
in with the production of slight traces of formic acid and 
marked reduction of the rotatory power of lactose; a brown 
color is produced at the same time. A deposition of salt and 
perhaps of albumin also takes place in the fat-globules, which 



234 THE ARTIFICIAL FEEDING OF INFANTS. 

increases their mean density, causing them to rise slowly to 
the surface when the milk is afterwards cooled. During the 
heating the fat-globules are expanding, and ma}' sometimes 
coalesce. It is not known how far the heating of milk affects 
its digestibility. Milk which has been heated is curdled less 
readily by rennet than fresh milk, but there are good grounds 
for the view that this is due to the deposition of calcium salts 
rather than to any change in the casein. It has been asserted 
that sterilized or boiled milk is digested more easily than raw 
milk, but this may be due to the fact that it does not curdle so 
easily in the stomach and does not produce so firm a clot. 

The Artificial Digestion of Raw and Sterilized Milk. 

Michel. 101 The author carried out experiments in Budin's 
laboratory with the artificial digestion of raw and sterilized 
milk: (1) with hydrochloric acid and pepsin; (2) with 
pancreatin in neutral or alkaline medium; (3) digestion of 
the curd produced by the action of the lab-ferment with pepsin 
and hydrochloric acid; (4) digestion of the curd so produced 
by pancreatin; (5) complex digestive processes with lab, 
hydrochloric acid, pepsin, and pancreatin. 

In his experiments the polarimeter was used to estimate the 
amount of peptones. The basis employed in the estimations was 
the ratio of the peptones to the total nitrogen. One gramme 
of nitrogen represents 6.41 grammes of peptones approxi- 
mately. The Kjeldahl method was used. 

I. Digestion was maintained in the incubator for nearly 
eight hours at 40° C. Eaw milk furnished 18.75 grammes 
of peptones; sterilized at 115° C, 17.53 grammes, the former 
showing somewhat more rapid digestion. 

II. Digestion for five hours gave 21.76 grammes for raw 
milk and 24.64 grammes when the milk was sterilized at 
115° C. 

III. Digestion in the incubator for three and a half hours 
at 40° C. gave 7.57 grammes for raw milk and 10.72 grammes 



STERILIZATION AND PASTEURIZATION. 235 

for sterilized milk. When the digestion was kept np for eight 
and a half hours, raw milk furnished 14.316 and sterilized 
milk twelve grammes of peptones. 

IV. The curd is digested much more rapidly by pancreatin 
when sterilized milk is administered (28.22 grammes) than 
when we give raw milk (13.12 grammes). 

V. The digestion of raw milk by lab-ferment, pepsin, and 
hydrochloric acid is slower in the first three hours than that 
of sterilized milk (9.59 grammes as against 11.32 grammes) ; 
at the end of six and nine hours it is more rapid, giving at 
the latter period 16.64 grammes as against 14.91 grammes. 
Further digestion with artificial pancreatic juice for six hours 
gave 21.76 grammes of peptones for raw milk and 24.57 
grammes for sterilized milk. 

Digestion of the Lactdlbumins. 
101 Sterilized milk contains almost no coagulated albumin; 
but in contact with the acid gastric juice the albumin of 
sterilized milk precipitates, while that of raw milk remains 
in solution. This albumin, whether in solution or not, is 
of long and difficult peptic digestion. The total of these 
experiments shows that sterilization does not injure, but 
rather increases the digestibility of the milk albuminoids. 
(? Editors.) 

Filtration through Cotton, and Centrifugation. 

Marfan believes that filtration through cotton, to be effica- 
cious, must slightly alter the constitution of the milk. If 
germs cannot pass, neither can all of the milk constituents. 
If the composition is not modified, neither is the bacterial 
find. 

Seibert has proposed filtration through moist cotton to free 
milk from germs, stating that the milk was not altered. Va- 
riot found this to be the case, but that the impurities passed 
through as well. Heat is the only satisfactory germicide. 



236 THE ARTIFICIAL FEEDING OF INFANTS. 

Seibert (Archives of Pediatrics, July, 1894) asserted that 
simple filtration through a half-inch layer of compressed ab- 
sorbent cotton reduced the number of bacteria from one-half 
to one-fourth the original amount. Kiliani confirmed his 
results. Biedert recommends centrifugation and filtering to 
remove dirt. 

Schoenlein found that after centrifugation, and when cream 
forms by the gravity process, the majority of the bacteria are 
found in the cream, very few in the dirt which is thrown out, 
and the remainder in the skimmed milk. 



CHAPTEE X. 
WEIGHT AND GROWTH OF THE INFANT. 

Monti." The body weight of a child born at term varies 
from two thousand five hundred to five thousand grammes, sel- 
dom exceeding the latter figures; three kilogrammes may be 
considered the average. Twins usually weigh only from two 
thousand to two thousand four hundred grammes ; children of 
primiparse generally from one hundred and seventy to one 
hundred and ninety grammes less than those of multipara?. 
Within a few hours of birth a loss of weight occurs, due to 
the evacuation of meconium (from sixty to ninety grammes) 
and the passage of urine (from ten to fifteen grammes), evapo- 
ration from the lungs and skin, and to the deficient intake of 
food during the first days of life. This diminution continues 
for two or three days, and is made up within from five to 
eight days. In the case of healthy infants at the breast it 
amounts to from one-fourth to one-sixteenth of the body 
weight, or on the average to from one hundred and seventy 
to two hundred and twenty-two grammes. In the case of the 
artificially fed child the loss in weight may last one or two 
days longer. The poorer the development or the less the body 
weight of an infant the longer will be the loss and the slower 
its equalization. In premature infants this is especially notice- 
able. Such may not regain their weight before the third or 
fourth week. Premature infants who are artificially fed may 
lose one-tenth of their original weight, and not regain it in 
five or six weeks ; they should therefore, whenever practicable, 
be given breast-milk. 

The increase in weight of infants at the breast during the 
first year follows one of three types. 

I. In a large series of cases the increase in weight proceeds 
regularly from month to month; this was first observed by 
Quetelet and Bouchaud. 

237 



238 THE ARTIFICIAL FEEDING OF INFANTS. 



Body weight in 
Age. 



One month 

Two months . . , 
Three months . . 
Four months . . , 
Five months . . . 
Six months 
Seven months . . 
Eight months . , 
Nine months. . . 
Ten months 
Eleven months . 
Twelve months. 



lily increase. 
Grammes. 


Monthly increase. 
Grammes. 


grammes. Origi- 
nal weight 3250 
grammes. 


25 


750 


4000 


23 


700 


4700 


22 


650 


5350 


20 


600 


5950 


18 


550 


6500 


17 


500 


7000 


15 


450 


7450 


13 


400 


7850 


12 


350 


8200 


10 


300 


8500 


8 


250 


8750 


6 


200 


8950 



II. Those cases where the increase in weight is progressive, 
diminishing from month to month, but in which the increase 
in weight is much greater during the first four months and 
smaller in the last months than in the preceding type. 



Fleischmann's Table. 


Daily increase. 


Monthly increase. 


Body weight at birth 


Age. 


Grammes. 


Grammes. 


3500 grammes. 


One month 


35 


1050 


4550 


Two months 


32 


960 


5510 


Three months 


28 


840 


6350 


Four months 


22 


660 


7010 


Five months 


18 
14 
12 


550 
420 
360 


7560 


Six months 


7980 


Seven months 


8340 


Eight months 


10 


300 


8640 


Nine months 


10 


300 


8940 


Ten months 


9 


270 


9210 


Eleven months 


8 
6 


240 

180 


9450 


Twelve months 


9640 







WEIGHT AND GROWTH OF THE INFANT. 239 

III. In this class belong those cases where the body weight 
does not increase regularly, but by fits and starts, and in which 
the greatest increase frequently occurs in the second or the 
fourth month and diminishes after that time. 

The following table is taken from Hahner, the child weigh- 
ing three thousand one hundred grammes : 



Daily increase. 
Grammes. 

One month 24. 5 

Two months 36.5 

Three months 20.5 

Four months ^ 15.6 

Five months 22.3 

Six months 10. 8 

Seven months 22. 5 

Eight months 14.0 

Nine months 9.0 

Ten months 10.3 

Eleven months 16.3 

Twelve months 10.0 



Monti, on the basis of his own experience, considers that 
the first type is characteristic of children who have the nor- 
mal average original weight and are fed regularly. The second 
type occurs in children who have higher original weight and 
are fed plentifully. The third type seems to occur only where 
the child has been overfed. The original weight may be normal 
or above it. 

From this it appears that the body weight of a child doubles 
in the first five months and triples at the end of the first year. 
The data here presented are of course only schematic. The 
conditions affecting the individual child, its hygienic surround- 
ings, the diet of the mother, correct or incorrect observance 



Monthly increase. 


Body weight. 


Grammes. 


Grammes. 


735 


3835 


1095 


4930 


610 


5540 


470 


6010 


670 


6680 


325 


7005 


675 


7680 


420 


8100 


270 


8370 


310 


8680 


490 


9170 


300 


9470 



240 THE ARTIFICIAL FEEDING OF INFANTS. 

of rules of feeding, etc., will all give a different weight-curve, 
which, notwithstanding the above conditions, must be consid- 
ered normal. Camerer gives, on the basis of weighings of 
fifty-seven children at the breast, with an original weight of 
three thousand four hundred and fifty grammes and over, the 
following tables, representing the weight in grammes at the 
end of the following weeks. 

I. 

At birth 1 2 4 8 12 16 20 weeks 

3450 3400 3490 3890 4680 5410 6090 6650 grammes 

24 28 32 36 40 44 48 52 weeks 

7130 7570 7990 8400 8580 9020 9300 9890 grammes 

Daily Increase in Grammes. 
4-8 8-12 12-16 16-20 weeks 

28 26 24 20 grammes 

28-32 32-36 36-40 40-52 weeks 
15 14 7 15 grammes 

In children whose weight at birth is subnormal the daily 
gain is usually less, and it approximates that of normal chil- 
dren only when it has regained the normal height correspond- 
ing to a child of that age. 

Fleischmann was the first to notice the constant rise and 
fall in body weight; Vierordt and Malling-Hansen have con- 
firmed Fleischmann's observations. Monti is also of the opin- 
ion that one must not assume for every child during the first 
year a steady increase in weight. The conditions of the day 
and year, the hygienic surroundings, the mother's diet, and 
anything affecting the child's environment must be considered 
in order to avoid error. 

The increase in weight is quite different in children on mixed 
feeding. They show variations and irregularities which appear 
in the following table : 





II. 


1-2 


2-4 


3 


29 


20-24 


24-28 


17 


15 



WEIGHT AND GROWTH OF THE INFANT. 



241 
















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16 



242 THE ARTIFICIAL FEEDING OF INFANTS. 

In artificially fed children the gain in weight during the 
first year is usually less than in children at the breast or in 
those getting mixed feeding. 

According to the condition of the digestive tract and the 
degree of absorption, the gain in weight of artificially fed 
infants is subject to manifold variations and disturbances. 
Monti's personal experience leads him to conclude that in 
artificially fed children the gain is seldom normal or reg- 
ular. 

Eussow has found that the weight of the hand-fed infant 
is not tripled before its second year. This difference is also 
observed in the later years of life, so that breast-fed infants 
in their fourth year weigh, on the average, two thousand 
grammes more than artificially fed infants. The same author 
gives the following table of the average gain in weight of 
children fed on cow's milk plus starchy foods: fifteen days, 
2900 grammes; three months, 4089 grammes; six months, 
4744 grammes ; eight months, 5254 grammes ; twelve months, 
6128 grammes; two years, 7430 grammes; four years, twelve 
kilogrammes; eight years, eighteen and three-tenths kilo- 
grammes. 

Camerer states that artificially fed children are backward 
in their development during the first half-year and weigh about 
one kilogramme less than breast-fed children of the same age. 
Monti takes exception to Camerer's statement that at the end 
of the first year hand-fed children have an equal weight with 
breast-fed children. He thinks that this occurs only excep- 
tionally. 

Weighings should be made every eight days at a fixed hour 
during the first year. Daily weighings give uncertain results. 

Cautley. 38 Three kilogrammes (six and a half pounds) 
is a fair average weight at birth, though often exceeded. 
There is a decided loss in weight during the first few days 
of life, which has been estimated by Haake, Quetelet, and 
Winckel at about half a pound. The prolonged presence of 



WEIGHT AND GROWTH OF THE INFANT. 243 

colostrum in mother's milk may induce a loss in infants who 
would otherwise gain. The passage of meconium and urine, 
the excretion of water by the skin and the expired air, the 
falling off of the cord, and the lack of food, all account for 
what may be termed the physiological loss, although this does 
not invariably occur. 

Stated roughly, the initial weight is doubled at five months 
and trebled at fifteen months. Eotch gives the following 
figures based on an original weight of from three thousand 
to four thousand grammes. From birth to five months the 
average gain per day will be twenty to thirty grammes, from 
five to twelve months the average gain per day will be ten 
to twenty grammes, and at one year a child ought to weigh 
nine and a half kilogrammes (20.9 pounds). Cautley deduces 
an average table from those of Sutils, Schmid-Monnard, 
Hahner, Eotch, and others. He estimates thirteen months 
of twenty-eight days each; the figures represent the weekly 
gain: 





Ounces. 




Ounces 


One month 


6 


Eight months 

Nine months 


... 3 A- 


Two months .... 


7 


... 2J 


Three months . . . 


6 


Ten months 


... 2i 


Four months .... 


5£ 


Eleven months 
Twelve months . . . 


... 2 


Tive months . . . 


5 


... 2 


Six months 


4i 


Thirteen months . . 


... li 


Seven months . . . 


4 







This amounts to a gain of about six ounces a week during 
the first three months, five ounces a week for the second three 
months, three ounces a week for the third three months, and 
two ounces a week for the remainder of the year. 

The increase of weight does not take place with such abso- 
lute regularity as indicated in the table, either in bottle-fed 
or breast-fed infants. To a certain extent the rate of gain 
is affected by the period of the year, attaining its maximum 



244 THE ARTIFICIAL FEEDING OF INFANTS. 

between July and October. Sunlight and fresh air are also 
beneficial and increase the rate of growth. The gain is not 
invariably proportionate to the initial weight. Infants ab- 
normally small at birth sometimes gain with much greater 
rapidity than those of a much larger initial weight. 

J. P. Ceozer Griffith/ 72 in an article in the New York 
Medical Journal for March 4, 1899, mentions the difficulties 
encountered in calculating the normal variations in weight 
during the first two years of life: the influence of feeding, 
the amount of food, defecation and urination, perspiration, 
and even the ordinary metabolic changes occurring during 
sleep. The child's weight is distinctly greater at night than 
in the morning. It seems impossible to apply the precise 
algebraic rule of Eaudnitz, based on a given age. The best 
that can be done is to determine the general average in a 
large number of cases and to represent it graphically in the 
form of a weight-chart. 

In generalizing methods a number of infants of a certain 
age are weighed. Another group, perhaps differing in number 
and age, are also weighed. The results are apt to be deceptive 
and do not represent true or normal conditions. 

" In Lorey's investigations, weighings of five hundred and 
sixtjr-five children were made by this method. In spite of 
this large number, it is quite evident that the irregularities 
which his weight-curves show, especially in the second year, 
do not represent the actual condition to be expected in the 
average child. In the combined curve for both sexes, for 
the second year, it appears that children at twenty-one months 
weigh less than they do at twenty months, and again less 
at twenty-four than they do at twenty-three months. This 
certainly does not represent the true state of the case. Lorey 
makes no claim that his figures yield any statistical results, 
although based on so many cases. 

" The individualizing method is better. The weighings of 
one child are recorded at frequent and regular intervals 



CHART I. 

WEIGHT IN FIRST 10 DAYS 



CO 

111 

S 
< 

DC 

CD 


DAYS 





1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


CO 

m 


N 

O 

12 
10 
























3,515 
3,459 


















































3,402 




8 




















































• 






















3,345 




6 


\ 






















\ 


























4 


V 


\ 
\ 












— GREG 


ORY 










\ 


\ 












S 














1 


\ v 












-KEZMA 


RSKY 






3,232 




2 


1 


\ \ 






















\ \ 


\ 




/, 


,s>- 






HOLT- 






3,175 


7 










,f 








/' 


^ 






V--. 


~~«f 












/' 




3,1 19 




14 


\ 


















-COMBY 




^ 1 
\1 












/ 
/ 








3,062 




12 


















VI 










// 










3,005 
2,948 




10 
8 






























// 


/ 














V 




s£ 


S* 














2,892 




6 






\/^ 


? 




















V 










































:-— HAA 


KE 


2,835 




4 
























\ 






















2,778 




2 


A 






















2,722 




14 

























CHART II. 

GAIN IN WEIGHT.- LOREY 



MONTHS 


1 


2 


3 


4 


5 


6 


7 


8 


S 


10 


11 


12 


13 


14 


15 


16 


17 


18 


19 


20 


21 


22 


23 


24 


12,000 


















































1 1,000 
10,000 


















































































A 




/ 


t 




fl 


1 1 


\ 

\ 


































/ 




4 












9,000 
8,000 




























A 




/ 


/ 
/ 




a 


! 




1 

1 

1 




I 


















/ 


A 


V 




/ 
/ 


\ 


\ 

\ / 


/ 










1 , 

\ 

i 






















































CO 

< 7,000 














^, 




/ 


' 


/ 






































ij 




































6,000 
5,000 












// 
/ / 

u 










































t 

1 


/ 
/ 


t I 












































! I 
1 / 












































4,000 




1 

1 l 
















































fr 


















































i 
i 


)YS 












































3,000 


J- 


-GIRLS 




























































































2,000 



















































WEIGHT AND GROWTH OF THE INFANT. 245 

throughout its infant life, and comparison is made with a 
large number of similar records of individual cases. The 
mean weights and the average rate of increase for different 
periods of the child's life can readily he computed. 

iC It has been of interest to me to compare the various tabu- 
lated observations which have been made in the effort to 
determine the growth of the child during the first two years 
of life. Perhaps the oldest and one of the most quoted tables 
of growth is that of Quetelet, but this is more ideal than 
actual, and, as plotted by Fleischmann, gives a straight line 
rather than the curve which represents the actual condition 
of affairs as now understood. The straight line results from 
the assumption that the rate of growth is the same for all 
periods of the first year. 

" A second much-quoted estimation is that of Bouchaud. 
Although his observations were made by the individualizing 
method, he has rounded off his figures to such an extent that 
his final table of growth is much too schematic. The plotted 
curve is, however, a more accurate representation than that of 
Quetelet, although it gives a rate of growth lower than may be 
expected of the average healthy breast-fed infant. 

" A table of weight, constructed by Fleischmann by the 
individualizing method applied to fifteen breast-fed children, 
is often referred to. I have plotted the curve derived from 
these figures in Chart II. It shows the rapidity of growth 
of the first months and the diminishing rate during the suc- 
ceeding months. 

" Eecently a useful curve has been published by Holt, con- 
structed apparently by the individualizing plan. 

" One of the most careful studies of the subject is that 
of Camerer. This observer has followed by the individualizing 
method the rate of growth of a large number of children 
during the first year of life, has studied the similar obser- 
vations of Fleischmann, Vierordt, and others, and has pub- 
lished several tables and curves which, on the whole, appear 



246 THE ARTIFICIAL FEEDING OF INFANTS. 

to be the most valuable we yet possess. Attention has been 
paid to the variations in initial weight and influence of these 
upon the later weights, and also to the nature of the food, 
whether human milk or cow's milk. Even Camerer's curves, 
however, have certain irregularities which prevent their being 
taken as types, — for which, indeed, they are not intended. 
In Chart II. I have plotted the curve of his figures for breast- 
fed children with an initial weight of over seven hundred 
and fifty grammes (six pounds and one ounce). Camerer also 
gives some estimations of the rate of growth during the second 
year (Chart II.). Another observation upon growth in the 
second year is that of Lorey, already referred to. In Chart 
II. I have combined his chart for boys and girls respectively 
during the second year, thus eliminating some of the irregu- 
larities. In all the curves represented in Chart II. all figures 
originally in the metric system have been reduced to avoir- 
dupois weight for the convenience of comparison. 

"The following weight-chart (IV.) has been constructed in 
the effort to represent as nearly as possible the average rate of 
growth of healthy breast-fed children. Although to a certain 
extent schematic, as any averaging chart of this nature must 
necessarily be, it is, I think, as accurate as can be expected 
of any one suited for practical purposes. It has been made 
after a careful study of most of the available published data, 
although it follows Camerer's curve more nearly than any 
other. 

" The fact that it is so often necessary to record the weight 
of poorly developed children during the second year necessi- 
tated the representing in this chart of the continuous growth 
during the first two years of life. The line passing obliquely 
through it represents, of course, the rate of growth of healthy 
breast-fed children. Bottle-fed babies, as a class, fall below 
this weight, yet by no means necessarily so. There is also 
some difference in weight depending upon sex, boys being 
generally heavier than girls. This difference may, however, 



WEIGHT AND GROWTH OF THE INFANT. 247 

be ignored in this connection. Each horizontal line repre- 
sents a difference of four ounces. A gain of two ounces or 
even less can be indicated by marking between the lines. 
The weight should be taken weekly and recorded by dots con- 
nected by a line, as in a temperature-chart. For convenience, 
the figures at the top show not only the weeks, but the 
months as well. In order to prevent the chart from becoming 
of an unmanageable size, the portion for the second year — 
since this will be needed less frequently — has been narrowed 
in such a way that the space for four weeks is of the same 
breadth as that for two weeks during the first year. This 
necessarily distorts the proper position of the plotted curve, 
and gives the erroneous impression to the eye that the child 
grows as rapidly during the second year as during the first. 
It is evident that if the spaces for the years were of equal 
breadth, the curve for the second year would be very much 
nearer a horizontal line. For practical purposes this distor- 
tion of the curve is of no moment, since its actual relation 
to the figures is unaltered. 

" There are a few matters remaining to which brief refer- 
ence must still be made. First, the birth-weight assumed 
(seven and three-fourths pounds) is somewhat more than that 
given by many writers, yet it agrees practically with the sta- 
tistics of Fleischmann, as also with those of Camerer for many 
of his cases. Should a child at birth weigh much less than this, 
it is to be expected that the rate of growth will be very much 
the same. This will give a curve slightly below that of the 
chart. But a child who weighs over seven pounds at birth 
may be expected to reach the full normal weight by the age 
of one year. 

" Then as to the loss in weight which the child suffers 
after birth before its regular gain begins. Although this does 
not necessarily take place, yet its occurrence is the rule and 
may be considered physiological. This was shown by the in- 
teresting experiments of Ingersley, who allowed sixteen chil- 



248 THE ARTIFICIAL FEEDING OF INFANTS. 

dren immediately after birth to be suckled regularly by women 
who had been confined a few da}^s before. The remarkable 
fact was noticed that the children showed not only a greater 
but a more prolonged loss of weight than the average. 

" There have been various estimations made of the degree 
and duration of loss. Some of these I have depicted in Chart 
III., including the observations of Gregory, Kezmarsky, Holt, 
Comby, and Haake. In all cases statistics in the metric 
system or, in the case of Haake, in the old German system 
of weights have been changed into pounds and ounces avoir- 
dupois. The curves of Gregory and Kezmarsky, it will be 
noticed, run much together. The first was based upon obser- 
vations made on thirty-three and the second on thirty-two 
healthy breast-fed children. Kezmarsky explains the greater 
duration of loss in his cases and the slower gain, as compared 
with Gregory's, on the ground that the children under his 
care were not nursed with the regularity which was desirable. 
In Gregory's they have nearly regained the normal weight 
by the seventh day; Kezmarsky's fall much short of this. 
These two curves are largely in accord with the observations 
of Winckel, and seem to represent the experience of most 
investigators. The curve representing the table of Comby 
seems to be largely schematic. I cannot find on what actual 
observations it is based. The curve of Holt represents his 
experience with a hundred healthy breast-fed children. It 
differs from the others in the greater degree of loss of weight, 
which equals ten ounces (two hundred and eighty-four 
grammes). This, however, is in accord with the observations 
of Townsend on the records of two hundred and thirty-one 
breast-fed children in the Boston Lying-in Hospital. Here 
the average loss was two hundred and seventy-nine grammes 
(9.8 ounces). I presume, however, that children suffering 
from illnesses were not excluded in making the computation. 
The observations of Haake on one hundred healthy breast-fed 
children, as shown in the curve, not only give a loss which 



CHART III. 



WEEKS 4| gl 12| 16 1 20 | 



2 3 4 5 6 7 8 9 10 11 1*2 1*3 ij* 1*5 1*6 17 l'8 ijfl 2*0 2J1 2& 23 24 

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92 ,96 100 104 



Weight-curves of C— Camerer. C2— Camerer, second year. F— Fleischmann. H— Holt. 
L— Lorey. B— Bouchaud. Q— Quetelet. 



CHART IV. 

infant's weight-chart. 

(Designed by J P. Crozer Griffith, M.D., Clinical Professor of Diseases of Children in 
the University of Pennsylvania.) 



Name- 



Date of birth- 



Months 123486789 ID 11 12 13 1415 16 17 18 19 20 2122 23 24 
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Pounds 

Weeks 1 35 7 9 1113 1517 19 2123 25 27 293133 3537 394143 4547 49 51 56 60 64 68 72 76 80 84 88 92 96100104 



mn 



BE 



£Z 



A 



WEIGHT AND GROWTH OF THE INFANT. 249 

is less than that -usually accepted as the common one. being 
but a hundred and sixty-three grammes (5.75 ounces), but 
also an initial weight lower than the average. 

" According to Fleischmann, who has made a careful study 
of various writers' estimations, the average total loss equals 
two hundred and twenty-two grammes (7.8 ounces). The dura- 
tion of loss is from two to three days, and sometimes longer. 
The total loss equals about one-fourteenth or one-fifteenth of 
the initial body weight. Increase in weight begins on the 
second to the fourth day, but the original weight is seldom 
regained before the eighth or the ninth day or even not before 
the tenth day. Chart IV. shows the approximate loss existing 
at the end of the first week, but not the greater loss which has 
taken place before this date. 

" Lastly, the variation in the weight-curve of any infant 
which a weight-chart will show must be borne in mind. Not 
only will there be a variation dependent upon the fulness 
of the stomach, bladder, and bowels, as already stated, but 
there is a variation which does not rest upon these factors 
and yet which cannot be called pathological. For instance, 
it not infrequently happens that a baby goes, it may be, a 
week without a gain in weight, or even shows a loss, and 
yet cannot be called ill. Yet such a condition should always 
arouse watchfulness. 

" The value of the systematic recordings of an infant's weight 
scarcely needs to be emphasized. Every physician especially 
interested in diseases of children fully recognizes it, for he 
knows that often a failure to gain, even before the child shows 
to the eye any ailment whatever, may be the sign that some 
form of illness is present or that the child is underfed. The 
weight-chart is even more valuable than the temperature- 
chart in the case of infants. The weighing, too, is such a 
simple matter that there is no excuse for a failure to have 
it carried out by the mother at least once a week, and where 
a change in the method of feeding is being made, twice a 



250 THE ARTIFICIAL FEEDING OF INFANTS. 

week. Good spring scales showing ounces are not expensive, 
or a steelyard or ordinary kitchen scales with weights will 
answer; but best are some of the standing spring scales fitted 
with an oblong basket or a scoop, and which are to be devoted 
solely to the weighing of the baby. 

" It is of course understood that the weight recorded is that 
of the child undressed. If undressing at every weighing is 
inconvenient, the child may be weighed when dressed and 
then when undressed, and the weight of the clothes deducted. 
At subsequent weighings, then, it is only necessary to see that 
the clothing is exactly similar, and undressing will not be 
required." 

Metabolism. 

Cautley. 38 " The child requires more food in proportion 
to its body weight than the adult. The relationship of the 
different constituents of its diet to one another also varies 
because of the extra need of heat-producing food during the 
early months of life, to counterbalance the deficient heat pro- 
duction from lack of muscular energy and the greater loss of 
heat by the skin proportionately to the bulk of the body. 

" Practically all foods may be considered to consist of five 
proximate principles : water, proteids, carbohydrates, fats, and 
salts. 

" Water. — Though water is not primarily a source of energy 
nor nutritious in the ordinary sense of the word, it is never- 
theless essential to life and constitutes more than half the 
entire body weight. Physiological activity of the cell depends 
upon a due supply of water. Proportionately to its weight, 
the infant requires much more than the adult; the relation- 
ship of the body surface to the body weight being considerably 
greater, therefore the loss of moisture by the skin is more in 
proportion. 

" To a large extent water assists in digestion ; it increases 
the secretion of pepsin and hydrochloric acid (Jacobi) and 
thus aids in proteid digestion ; it is of great value as a solvent 



WEIGHT AND GROWTH OF THE INFANT. 251 

and diluent of food substances and thus assists in absorption 
from the alimentary canal; it promotes the activity of the 
circulation of fluids, increases cell metabolism, and aids elimi- 
nation; as a diluent of the intestinal contents it helps to 
prevent constipation. 

" Proteid is the form of food in which nitrogen is supplied 
to the body. Nitrogenous matter is essential to the structure 
of protoplasm and enters into the structure of every cell. All 
the tissues of the body are formed by cells or modifications 
of cells, and consequently the child requires even more pro- 
teid, in proportion to its weight, than the adult, who has only 
to maintain equilibrium of tissue, whereas the infant has to 
provide for the building up of new tissue. An adult man of 
sixty-seven kilogrammes weight requires about a hundred 
grammes of proteid daily. An infant of 6.7 kilogrammes (the 
weight of an infant about six months old) takes one thousand 
grammes of milk daily, containing twenty grammes of pro- 
teid ; much more proportionately than the adult. So, too, the 
growing child requires a free supply of proteid food, more pro- 
portionately than the adult, and yet very commonly gets less. 

" Animal proteids are more digestible than vegetable pro- 
teids, and, as a rule, the more they are altered by cooking 
the more difficult of digestion they become. The chief animal 
proteids are the myosin of meat, the casein and lactalbumin 
of milk, and the various proteids of blood. All the proteids 
taken into the stomach are not necessarily digested and as- 
similated; even in an infant at the breast a considerable pro- 
portion of the proteids may be found in the faeces. 

"When the proteids of the food are deficient, the child 
becomes anaemic, languid, debilitated, and short of breath on 
exertion. The muscles are soft and flabby and the child ceases 
to grow. Too great a proportion of proteids, on the other 
hand, leads to indigestion, colic, and constipation, especially 
when the casein is in excess. 

" Fat. — The two great food-stuffs for the production of 



252 THE ARTIFICIAL FEEDING OF INFANTS. 

heat are the fats and the carbohydrates, and of the two the 
fat is more valuable by virtue of the large amount of carbon 
which it contains. Fats are much poorer in oxygen and 
richer in carbon and hydrogen than the carbohydrates, and 
therefore their heat value is proportionately greater. Heat 
is essential to life, and all the vital processes are more active 
at the temperature of the body than at a lower temperature. 
This is more especially the case with the muscular and nervous 
systems. Although we have no proof that the fat in the tissues 
is formed from the fat taken in as food, it is well known that 
the fat stored up is soon drawn upon if the food is deficient, 
and hence the tissues may suffer indirectly. An infant of 
6.7 kilogrammes takes in its milk forty grammes of fat, 
whereas an adult weighing ten times as much does not re- 
quire more than one hundred grammes. The reason for this 
is that the infant cannot maintain its bodily temperature by 
exercise in the same way as the adult. 

" Attempts have been made to remedy deficiency of fat in 
the infant's diet by the addition of carbohydrate food. Such 
a substitution is theoretically sound if fat is regarded as a 
source of heat only, and the proportion of additional carbo- 
hydrate required for this purpose can readily be calculated. 
Clinical results prove, however, that such a substitution is un- 
satisfactory, and that carbohydrates cannot replace fat to the 
advantage of the child. The best evidence of this is the preva- 
lence of rickets among infants brought up on sweetened con- 
densed milk. 

" Artificial mixtures, as usually ordered, rarely contain such 
an excess of fat as to cause gastro-intestinal disturbances. 
Such results do occasionally occur in infants brought up at 
the breast where the mother's milk contains abnormally high 
percentages of fat. Generally at the same time there is an 
excessive proportion of proteids, so that it is difficult to ascer- 
tain to which excess the digestive disturbance is due. 

"Too free an administration of fat in the food may give 



WEIGHT AND GROWTH OF THE INFANT. 253 

rise to a variety of diarrhoea described by the Germans as 
*' fat diarrhoea/ and characterized by the presence of a large 
quantity of fat in the stools. It is usually associated with 
simple intestinal catarrh. 

" Sugar. — Carbohydrates are of value for the production 
of heat and as a source of muscular energy. The infant 
weighing 6.7 kilogrammes takes about seventy grammes of 
carbohydrate in its milk; the adult of ten times the weight 
requires about two hundred and forty grammes and more in 
proportion to the amount of muscular work he performs. 

"Infants at the breast practically never suffer from defi- 
ciency of carbohydrate food, the percentage in human milk 
varying within comparatively small limits; in artificial feed- 
ing there is more commonly an excess. 

" Nearly all the patent foods and condensed milk on the 
market contain an excess of carbohydrates, generally in the 
form of starch or cane-sugar. Almost all the infants fed upon 
these foods become fat, flabby, unwieldy, and rachitic. In- 
testinal disturbances are also frequently induced. 

" Salts. — Bunge was the first to establish the remarkable 
fact that the percentages of salts in the ash of the new-born 
animal are practically the same as the percentages of ash in 
mother's milk. Certain exceptions are noticeable and im- 
portant. The ash of the milk contains more potassium and 
less sodium salts, which may be explained by the fact that, as 
the animal grows, there is a relative increase in the muscles 
which are rich in potassium and a diminution in the carti- 
lages which are rich in sodium. 

" Another important difference is the percentage of iron. 
The proportion of iron in the ash of the new-born animal is 
very much greater than in the ash of mother's milk. The 
latter deficiency is counteracted by the young animal storing 
up iron in its liver previous to its birth. Bunge has found 
that the proportion of iron in the ash of animals of the same 
litter diminishes with the increase in the growth of the ani- 



254 THE ARTIFICIAL FEEDING OF INFANTS. 

mal, showing that this previously stored-up iron is required to 
make up for the deficiency of iron in the mother's milk. 

" Sodium Chloride. — Cow's milk contains so much more 
sodium chloride than mother's milk that it is not necessary 
to add common salt to cow's milk in artificial feeding. [The 
analyses of Harrington and Kinnicutt and Soldner give con- 
trary results. — Editors.] The addition of salt, however, has 
some advantages. It acts as a stimulant to the appetite and 
increases the secretion of hydrochloric acid, thus assisting in 
digestion. It aids in the solution of globulins in the blood; 
this group of proteids being insoluble in distilled water, but 
soluble in dilute alkaline solutions. When added to milk, salt 
diminishes its coagulability with rennet ferment and gastric 
juice, and may therefore be of advantage in feeding infants 
with weak digestions. 

" It is a curious fact that all carnivorous animals require 
no additional salt with their food. Herbivorous animals take 
a considerable quantity of it, in proportion to the amount of 
vegetable food ingested. Vegetable food contains much potas- 
sium salt, and the sodium salt is required to neutralize its 
effects. It is important, therefore, to add salt to the diet 
of an infant who is given vegetable food with its diet, such 
as barley-water, etc. There is one cereal which contains re- 
markably little potassium, — namely, rice. 

" Iron. — Both human milk and cow's milk contain a very 
small proportion of iron, — namely, 0.003 per cent, of the dried 
solids; hence, when cow's milk is diluted, the percentage of 
iron is reduced below that of mother's milk. Deficiency of 
iron in the food of the hand-fed baby may produce anaemia 
and debility. To guard against this, iron must be given by 
the mouth, and, seeing that normally it is taken in the form 
of organic compounds, it is better to administer it in this 
form rather than give inorganic preparations. It is doubtful 
whether iron introduced in the form of inorganic salts can 
be converted into haemoglobin by synthesis. Organic ferru- 



WEIGHT AND GROWTH OF THE INFANT. 255 

ginous combinations exist in the yolk of an egg in the form 
of nucleo-albumins, analysis showing that 0.04 per cent, of 
the dried solids of the egg-yolk consist of iron. 

" In blood and raw meat juice iron is contained in consider- 
able quantity in the form of haemoglobin. In this combina- 
tion the iron is more firmly held than in the nucleo-albuminous 
compound present in the yolk of the egg. Nevertheless, raw 
meat juice or the gravy of undercooked meat is a valuable 
addition to the diet of an infant for the prevention and cure 
of anaemia. After the age of one year potatoes (containing 
0.042 per cent, of iron in the dried solids) can be added to 
the diet. About 0.02 per cent, of iron is present in lean meat, 
cereals, and leguminosae, such as wheat and peas. 

" Lime. — In human milk 0.0243 per cent, of lime is present, 
in cow's milk 0.151 per cent., and in the yolk of egg 0.38 per 
cent. Meat, cereals, and leguminosae contain a much smaller 
proportion, and it is doubtful whether a child brought up on 
a diet devoid of milk would obtain the amount of lime requi- 
site for the proper development of its bones. It is uncertain 
whether this salt can be absorbed except in the form of organic 
compounds, and it is exceedingly improbable that it is ab- 
sorbed dissolved in water. There is no evidence that water 
rich in lime salts has any value whatever in the prevention of 
rickets. 

"Lime-water in saturated solution contains less lime than 
cow's milk; consequently, the addition of this fluid to milk 
can exert no influence, except by virtue of its alkalinity. Lime 
is more soluble in cold than in hot water, so that when lime- 
water is added to hot milk, some of the salt is precipitated. 
The lime salts in milk are rendered more insoluble by pro- 
longed heating, as in sterilization. 

" Phosphorus is of the utmost importance in the formation 
of bone and probably in the prevention of rickets; so much 
so that in recent years it has been prescribed for rickets and, 
according to some authors, with considerable success. Six 



256 THE ARTIFICIAL FEEDING OF INFANTS. 

times as much phosphorus is present in lean beef, yolk of 
egg, and cow's milk as is found in mother's milk. Cereals, 
leguminosse, and potatoes contain considerably more phos- 
phorus than human milk. Lecithin and nuclein are bodies con- 
taining phosphorus, and are found in considerable quantities in 
nervous tissues and ova. It is not known whether they are ab- 
sorbed and digested, but the administration of calves' brains 
and hard roes of fish is certainly harmless. The large amount 
of phosphorus present in cow's milk indicates that ordinary 
dilutions will Dot render the supply of this salt deficient. If 
it is thought that more is required, it is much simpler to 
administer the salt in the form of the yolk of egg than in 
the form of inorganic compounds, and in all probability this 
is better digested and assimilated." 

In order to compare the constituents of an average adult 
diet and that for an infant of six months, weighing 6.7 kilo- 
grammes, we have taken the average of the figures given in the 
estimations of von Eanke, Moleschott, Pettenkofer and Voit, 
and Waller (cited by Cautley), and those for an infant's diet 
as estimated by Cautley, allowing that a healthy infant aged 
six months takes a litre of milk daily, and calculating from 
Leeds's average analysis of human milk. 



Proteids 

Fat 

Carbohydrates 

Salts 

Water 



" On comparing the latter with the adult diet it is seen that 
the infant requires a much more liberal supply of each of 
the constituents of the ordinary diet in proportion to its 



Constituents of an 

average adult 

diet. 


Diet of an infant aged 

six months. Weight, 

6.7 kilogrammes. 


Grammes. 


Grammes. 


121 


20 


94 


40 


350 


70 


26 


2 


2629 


868 



WEIGHT AND GROWTH OF THE INFANT. 257 

weight, and a much more liberal supply of fat and water com- 
pared with its need for proteids. Halliburton estimates the 
needs of an infant under a year and a half old as from twenty 
to thirty-six grammes of proteids, thirty to forty-five grammes 
of fat, and sixty to ninety grammes of carbohydrates. At 
present it is impossible to give more definite figures, and it 
must be remembered that the requirements of the individual 
child may vary to some extent from the average. In regard 
to proteids, Waller has pointed out that in proportion to body 
weight the amount required by the infant is greater than that 
required by the adult, but that in proportion to the body sur- 
face the amount is approximately the same. Body surface is 
therefore a better proportional indication than body weight." 

KicmiOND. 121 Milk is of value as a food both to repair 
tissue waste and as a source of energy. Of its three main 
constituents : 



Fat contains 


Carbon. 
Percent. 

75.63 


Hydrogen. 
Per cent. 

11.87 
6.43 
7.13 


Nitrogen . 
Per cent. 

15.77 


Oxygen. 
Percent. 

12.50 


Sugar contains 

Proteids contain 


42.11 

52.66 


51.46 
22.77 



Fat is richest in carbon and hydrogen, proteids come next, 
while sugar occupies the lowest place. Neither fat nor sugar 
can replace the proteids, as these furnish the only source of 
nitrogen. It is evident that, to build up tissues containing 
high percentages of carbon and hydrogen, fat is a far more 
advantageous food than sugar. The value of milk as a food 
for infants depends largely on the fat present, and it is doubt- 
ful whether fat can be replaced by sugar without detriment 
to anabolic processes. 

Strohmer has given the following table of the values for 
combustion of the constituents of milk: 

17 



258 THE ARTIFICIAL FEEDING OF INFANTS 
Fats 



Sugar . . 
Proteids 



Butter furnishes 9231.3 calories per kilogramme 

Other fats furnish 9500 calories per kilogramme 
( Lactose furnishes 3950 calories per kilogramme 
( Cane-sugar furnishes 3955 calories per kilogramme 
f Casein furnishes 5858.3 calories per kilogramme 

( Albumin furnishes 5735.2 calories per kilogramme 



These rallies assume that complete combustion takes place. 
This may be said to be true for fat and sugar; when we 
consider the proteids, we must remember that the nitrogen 
is not excreted as such, but as compounds, of which urea may 
be taken as a type. The heat of combustion of the urea from 
one gramme of proteids amounts in round figures to fifteen 
per cent, of the total heat of combustion. It is necessary, 
therefore, to deduct fifteen per cent, of the heat of combus- 
tion of proteids in calculating isodynamic metabolic ratios. 

In round figures the following will be the calories per kilo- 
gramme developed in combustion of the three constituents 
in the human body: fat 9230, sugar 3950, proteids 4970. 

The author proposes to calculate the ratio between the 
various constituents as follows : 

Anabolic ratio = fat : sugar : proteids ; or, 2.38 : 1 : 1.26 

, r . , ,. .. fat X 2.38 + sugar + proteids X 1-26 

Metabolic ratio = ^ = r^ — 

proteids 

Instead of the above figures, the round figures 2.5 and 1.25 
may be used without appreciable error. 

The ratios of mother's milk are : Anabolic ratio = 2.2 : 4.5 : 1 

Metabolic ratio = 11.3 

The ratios of cow's milk are : Anabolic ratio = 1.15 : 1.4 : 1 

Metabolic ratio = 5. 54 

In calculating these ratios it is assumed that the constituents 
are all digestible. The marked difference is due to the smaller 



WEIGHT AND GROWTH OF THE INFANT. 259 

amount of proteids in human milk. Experiments have shown 
that children do not derive the most benefit from milk unless 
the anabolic ratio approximates 2 : 4 : 1 and the constituents 
are of such a form that they are as finely divided as possible 
in the stomach. 

The condition of the proteids necessary to produce a fine 
state of division in the stomach is attained by : 

I. Simple dilution with water and the addition of fat and 
sugar. 

II. Removal of casein and the addition of fat and sugar. 

III. By acting on milk with a proteolytic enzyme — i.e., 
peptonizing it — and the addition of fat and sugar. 

IV. By adding a preparation of diastase and diluting it 
and the addition of fat and sugar. 

Marfan". 105 Metabolism experiments have proved conclu- 
sively that the healthy adult organism needs for its proper 
development and growth the five principal food elements, all 
of which are contained in milk, — namety, fat, proteids, sugar, 
water, and mineral salts. Nothing can take the place of the 
proteids, salts, and water. To a certain extent, fat and sugar 
may be substituted for each other, but any attempt at abso- 
lute replacement of the one by the other is sure to lead to 
digestive disturbances. Water serves as a substratum for nearly 
all of the chemical changes of the human body. It helps to 
eliminate the products of metabolism, it keeps the alveolar 
surfaces moist, thus favoring the diffusion of gases in the 
lungs, and it plays a considerable role in favoring evaporation 
from the surface of the body. It is thus a factor in the regu- 
lation of the animal heat. Forster found that animals fed 
on foods containing no mineral salts wasted and died in a 
short period. 

The principal physiological characteristic of infancy is that 
during this period growth is more rapid than at any subse- 
quent period of life, and is the more rapid the younger the 
child. For example, the child doubles its weight in five months 



260 THE ARTIFICIAL FEEDING OF INFANTS. 

and triples it in fifteen months; consequently, assimilation 
predominates largely over disassimilation. To establish the 
balance of nutrition in the first period of infancy we must 
note: first, the quantity of food to be taken; second, the 
increase in weight; third, the number of calories consumed 
by the infant organism; fourth, the amount of urea, water, 
and carbon dioxide excreted. Unfortunately, on the last two 
points our knowledge is still imperfect. For example, a 
breast-fed infant in good health, weighing on the average five 
kilogrammes, will take in twent}^-four hours about eight hun- 
dred grammes of milk, and will gain from twenty-five to 
thirty grammes a day. The breast-milk which he takes con- 
tains in each one thousand grammes fifteen parts of casein, 
forty parts of fat, and sixty-three parts of sugar. The adult 
ingests daily for each kilogramme of his body weight one and 
seven-tenths grammes of albumin, 0.85 gramme of fat, and 
seven and a half grammes of carbohydrates. The infant in- 
gests per kilogramme twice as much albumin and five times 
as much fat as the adult (the quantity of milk-sugar being 
estimated as fat by multiplying by the ratio ten to twenty- 
four). Assimilation is thus very active in the first period 
of life. The ratio of the nitrogenous to the non-nitrog- 
enous elements in the diet is as one to five in the adult's 
food, one to six in woman's milk, and one to three in cow's 
milk. 

According to Lambling (Le Nord Medical, January 1, 1898), 
an infant consumes up to the age of two years one hundred 
calories per kilogramme per day. This is double the number 
of calories which would suffice for an adult engaged in moder- 
ate work. Eubner thinks that the greater extent of the body 
surface in infants as compared with their weight causes them 
to lose much larger amounts of heat during the same periods 
of time. Lambling has observed that if we compare the num- 
ber of calories consumed, not to the unit of weight but to the 
unit of surface, we find that the experiments give the same 



WEIGHT AND GROWTH OF THE INFANT. 261 

results for the infant as for the adult. He has estimated the 
proportion of heat furnished by the different elements of 
milk. In one hundred calories furnished to the organism, 
the following is the ratio of the different elements in the 
food: 



Adults. Infants. 

Proteids 19 18 

Fat 30 53 

Carbohydrates 51 29 

During the first year the infant consumes one hundred 
calories per day; from two to five } r ears, eighty to ninety; 
from five to twelve years, sixty to eighty. The adult consumes 
proportionately more carbohydrates than the infant, the latter 
almost double the quantity of fat consumed by the adult. 
This preponderance of fatty substances is to check albuminous 
waste in the tissues of the body; part of the fat must be re- 
tained to build up the growing structures. After weaning, 
when the milk is no longer the sole diet, the combustion of fat 
is replaced more and more by combustion of carbohydrates. 
The carbohydrates increase until they preponderate as in the 
adult. 

After the first year development is less rapid, and the supply 
of albumin and fat diminishes, while that of the carbohydrates 
increases until it is finally almost double that of the fat 
and albumin together. At the same time metabolism is 
still very active. From one to two years the infant absorbs 
per kilogramme twice as much albumin as the adult, three 
times as much fat, and one and a half times as much carbo- 
hydrates. 

The alimentary needs of infants at different ages have been 
calculated by Marfan as follows, on the basis of the researches 
of Camerer, Forster, Uffelmann, Voit, and Eiedel. 



262 



THE ARTIFICIAL FEEDING OF INFANTS. 



Age. Weight. 

Kilos. 

Three days 3.00 

Six days 3.2 

Three weeks 3.5 

Seven to ten weeks 4.00 

Four months 6.00 

One and a half years 9.00 

Two and a half years 10.00 





Per kilogramme. 




Albumin. 


Fat. 


C; 


ubohydrates. 


Grammes. 


Grammes. 




Grammes. 


2.4 


2.8 




2.9 


3.7 


4.3 




4.4 


4.8 


5.6 




5.7 


4.5 


5.2 




5.4 


3.8 


4.5 




4.6 


4.4 


4.0 




8.9 


3.6 


2.7 




15.0 



With regard to the need of salts for the infant's nutrition, 
we note that the child fed on milk obtains per kilogramme 
of body weight a greater proportion of mineral salts than the 
adult on an ordinary diet. The organism at first needs a 
considerable quantity of inorganic salts to build up the grow- 
ing tissues, whereas the adult body can keep itself in equilib- 
rium on a smaller quantity. 

During the first year the infant takes on the average four 
grammes of albumin per kilogramme of body weight, — i.e., 
twice as much as the adult. Up to five or six months urinaly- 
ses show that the infant eliminates less urea per kilogramme 
than the adult in nutritive equilibrium (see J. Renault, Traite 
des Maladies de VEnfance, vol. iii. p. 259). Towards fifteen 
months the infant eliminates more urea than the adult, and 
the quantity increases up to ten years, to fall subsequently 
and reach the ratio of adult life; proportionately the infant 
ingests more nitrogenous material than he eliminates (Carron 
de la Carriere et Monfet, " The Normal Urine of the Infant 
after Fifteen Months," Academie de Medecine, July 20, 
1897). These facts are in accord with the results obtained 
by weighing. During the first six months growth is more 
rapid and more nitrogen is retained than during the second 
six months of the first year. 

The researches of Voit and Pettenkofer, Forster, and more 



WEIGHT AND GROWTH OF THE INFANT. 263 

recent ones by Mensi, of Turin, are in accord in showing that 
the infant organism from birth to ten years eliminates from 
one and a half to two and a half parts more carbon dioxide 
than the adult organism. This excessive carbonaceous waste 
perhaps occurs at the expense of fat, thus serving to economize 
the albumin needed for growth. Munk, however, attributes 
it in part to the decomposition of albuminoids. He bases this 
statement on the fact that in infants carbon dioxide elimina- 
tion is parallel to that of urea (Munk and Ewald's Treatise 
on Dietetics). 

Phosphorus and Nitrogen Metabolism. 

Arthur Keller. 185 Two observations were undertaken to 
determine the amount of nitrogen excreted in the intestinal 
secretions and epithelia. In each case the infant was kept for 
two days on a starvation diet of sugar and water. The results 
gave 1.007.2 and 1.1618 grammes dried faeces respectively, with 
0.0716 and 0.0966 gramme nitrogen. While these figures are 
of course not of general application, they show at least that 
the amount of nitrogen so excreted is not inconsiderable as 
compared with the small total content of nitrogen in the 
faeces. 

The absorption of nitrogen may be said to be in general 
better on a diet of cow's milk than on one of breast-milk. 
Among breast-fed children the healthiest show the highest 
figures. Shortening of the pauses between feedings was with- 
out influence on the amount of nitrogenous absorption, as was 
also the addition of sodium phosphate to the diet. 

The* absolute amount of nitrogen retention depends to a cer- 
tain degree on the amount of nitrogen in the food, but depends 
also on the kind of food. When we consider the percentage 
figures of retention, we find that a greater proportion of the 
food nitrogen is retained on a diet of mother's milk than on one 
of cow's milk. Sick children utilize the nitrogen of mother's 
milk just as well as healthy ones ; on the other hand, the state 



264 THE ARTIFICIAL FEEDING OF INFANTS. 

of the child's health affects quite markedly its power to assimi- 
late the nitrogen of cow's milk. It is also remarkable that when 
sodium phosphate is added to the food, the utilization of nitro- 
gen is better than in all other cases. 

From the tables cited by the author it appears that two in- 
fluences are of moment for the utilization of nitrogen by the 
infant organism: the kind of food and the condition of the 
child's health. Other factors (even the amount of food), unless 
marked differences exist, possess less importance. 

Animal experiments, investigations on the adult, and metab- 
olism experiments on the infant justify the conclusion that 
the differences in nitrogen metabolism are due, not so much to 
the different constitution of the albuminous bodies in the two 
kinds of milk as to the variations in milk-sugar and fat con- 
tent. 

The results and conclusions to be drawn from tables repre- 
senting the sum of metabolism experiments of different ob- 
servers on different infants fed on different kinds of food at 
different times of life and under varying surroundings are 
to be accepted with reserve. They become of more value when 
we can control them by experiments carried out on the same 
child. Keller found that in the case of a child fed first on 
breast-milk and then on cow's milk, in the latter period less 
nitrogen was absorbed but more was assimilated than in the 
former. This observation applies as well to the healthy as 
to the sick child. 

The addition of carbohydrates to cow's milk, in the form 
of maltose or milk-sugar, diminishes the absorption but at 
the same time heightens the retention of nitrogen. In cor- 
respondence with these results, it is probably true that the 
higher percentage of milk-sugar in mother's milk shares in 
bringing about the greater retention of its nitrogen. 

Of the nitrogen in the starch, a decidedly smaller part is 
absorbed (at any rate, in the case of infants) than of the 
nitrogen in mother's milk. 



WEIGHT AND GROWTH OF THE INFANT. 265 

When malt soup is given, in which one-fourth of the nitrogen 
comes from the starch, only a smaller proportion of the nitro- 
gen administered will be absorbed, but, notwithstanding, more 
nitrogen will be assimilated than if we gave the same amount 
in the form of cow's milk. 

Up to the present we have no knowledge of the influence of 
the fat content on the assimilation of nitrogen. 

The addition of salts to the food increases the retention 
of nitrogen, whereas the addition of hydrochloric acid (Raud- 
nitz) does not affect it. 

Phosphorus Metabolism. 

Keller finds that the quantity of phosphorus administered 
in the food is no criterion for the amount of absorption and 
retention of phosphorus, but that other influences, such as 
the kind of food and the state of the child's health, are of 
more moment. 

In the case of normal healthy infants these experiments 
prove quite conclusively that the organic phosphorus combina- 
tions of woman's milk, as well as those of cow's milk, become 
soluble in the digestive fluids. The amount of phosphorus 
present in the faeces of healthy breast-fed children is very 
small; besides this, a considerable part of this phosphorus 
comes from the digestive juices and the intestinal epithelium. 
The experiments show that the phosphorus in woman's milk 
can be absorbed almost completely by the healthy child. The 
same can be said for the phosphorus in cow's milk. The 
experiments also show that absorption is somewhat more com- 
plete in the case of the artificially fed child, but retention 
of the food phosphorus decidedly less than in the case of 
the child at the breast. The differences in phosphorus metab- 
olism are more conspicuous in the case of sick children, and 
here the advantage is again with the nursing child. If we 
are forced to nourish such a child artificially, favorable con- 
ditions for phosphorus retention are furnished by a food which 



266 THE ARTIFICIAL FEEDING OF INFANTS. 

contains a plentiful amount of phosphates, besides phosphorus 
in organic combination. 

Keller reviews the metabolism work of Bendix, Lange and 
Berend, and some of his own experiments, and concludes that 
the results are contradictory and unsatisfactory. There is 
not enough in them to be made the basis of any definite con- 
clusions. Clinical observation is at present the only reliable 
guide, and it speaks against excessive administration of pro- 
teids. 

The metabolism experiments of Eubner and Heubner com- 
prise three cases, all of which were studied with the greatest 
care. A full account of them can be found in the Zeitschrift 
fur Biologie. While such experiments are of great interest, 
and may in the course of time reach a sufficient number to 
be of value to the practitioner in giving him a basis on which 
he may be able to calculate the needs of the organism in food- 
stuffs, as they are at present carried out, metabolism experi- 
ments on the infant do not approximate sufficiently to the 
normal conditions to be considered final, and we must be very 
cautious in drawing far-reaching conclusions from the results 
of a few isolated cases under varying conditions as to the 
child's age, diet, environment, etc. 

Blauberg 193 investigated the mineral salt metabolism in 
two cases, both healthy, one breast-fed and the other taking 
pure cow's milk; also the mineral metabolism in an atrophic 
infant. " Up to a certain degree the conclusion seems justified 
that too great a dilution of cow's milk has an unfavorable 
influence on the absorption of the mineral salts of the same. 
... In general, we may safely say that the salts of woman's 
milk are much better absorbed by the infant than those of 
cow's milk." 

Monti." A milk mixture prepared according to Heub- 
ner's method, consisting of equal parts of milk and water and 
enough milk-sugar to bring the strength of the solution up 
to six per cent, sugar, will contain the following values of 



WEIGHT AND GROWTH OF THE INFANT. 



267 



albumin, fat, and sugar, proportionately to the amount of 
food taken. 



Aee No " of cc - 
per meal. 

One week 30.0 

Two weeks 45.0 

Three weeks 45.0 

Four weeks 60.0 

Five weeks 75.0 

Six weeks 90.0 

Seven weeks 105.0 

Eight weeks 120.0 

Nine weeks 135.0 

Ten weeks 150.0 

Eleven weeks 165.0 

Twelve weeks 180.0 

Thirteen weeks 190.0 

Fourteen weeks 200.0 



No. of 
meals. 


Total daily 

amount. 

Cc. 


8 


2405) 


8 


360.0 


-7 


315.0 


7 


420.0 


7 


525.0 


7 


630.0 


7 


735.0 


7 


840.0 


7 


945.0 


7 


1050.0 


6 


990.0 


6 


1080.0 


6 


1140.0 


6 


1200.0 



Proteids. 


Fat. 


Sugar. 


Per cent. 


Per cent. 


Per cent 


4.08 


4.39 


14.06 


6.12 


6.58 


21.09 


5.27 


5.67 


18.16 


7.14 


7.68 


24.61 


8.84 


9.36 


30.16 


10.71 


11.52 


36.54 


12.41 


13.14 


42.34 


14.28 


15.12 


48.72 


15.98 


16.92 


54.52 


17.85 


18.90 


60.90 


16.83 


17.80 


57.42 


18.30 


19.44 


62.64 


19.38 


19.52 


66.12 


20.40 


21.60 


67.60 



Biedertfs Cream Mixture?* 







Weight ix grammes of 
differext coxstituexts. 


Percextage of 
differext cox- 
stituexts. 




Xo. of 






Sugar 










Age. 


mix- 
ture. 


Cream. 


Water. 


of 
milk. 


Milk. 


Casein. 


Fat. 


Sugar. 


One week 


1 


125 


375 


15 




1.0 


2.5 


4.0 


Two weeks 


2 
3 


125 
125 


375 

375 


15 
15 


60 
125 


1.4 

1.8 


2.7 

2.7 


3 8 


Three to four weeks . . . 


3.8 


Five to six weeks .... 


3 


125 


375 


15 


125 


1.8 


2.7 


3.8 


Seven to eight weeks. . 


4 


125 


375 


15 


250 


2.3 


2.9 


3.8 


Nine to ten weeks 


5 


125 


375 


15 


375 


2.6 


3.0 


3.9 


Eleven to twelve weeks 


6 




250 


10 


500 


3.2 


2.8 


4.0 



268 



THE ARTIFICIAL FEEDING OF INFANTS. 



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WEIGHT AND GROWTH OF THE INFANT. 269 

Monti." Ppeiffer estimates the values of the different 
constituents of mother's milk in the subjoined table. 



A- e Total 
° ' amount. 

Cc. 

One-half week 104 

One week 254 

Two weeks 334 

Three weeks 449 

Four weeks 550 

Five to six weeks 749 

Seven to eight weeks 864 

Nine to ten weeks 926 

Eleven to twelve weeks 896 

Thirteen to fourteen weeks 966 

Fifteen to sixteen weeks 974 

Seventeen to eighteen weeks 996 

Nineteen to twenty weeks 996 

Twenty-one to twenty-four weeks . 1023 

Twenty-five to twenty-eight weeks 1051 

Twenty-nine to thirty-two weeks . 741 

Thirty-three to thirty-six weeks . . 482 



No. and 
size of 
meals. 


Proteids. 


Fat. 


Sugar. 




Per cent. 


Percent. 


Percent 


8x 13 


4.40 


2.81 


4.69 


7x 36 


8.74 


6.86 


11.44 


7x 48 


7.64 


12.13 


15.05 


7x 68 


10.27 


12.13 


20.23 


7x 71 


12.58 


17.86 


24.78 


7x107 


13.82 


22.52 


41.47 


7 x 123 


15.83 


26.40 


45.03 


7 x 132 


17.68 


20.43 


55.28 


7x128 


17.10 


20.25 


53.50 


7x138 


19.53 


39.02 


59.12 


7x139 


19.62 


39.23 


59.39 


7x142 


17.38 


52.36 




7x142 


17.42 


52.28 




6x167 


15.82 


26.88 


60.00 


6x174 


11.99 


34.77 


60.40 


6x123 


12.15 


28.69 


42.80 


6x 88 


7.26 


11.62 


28.94 



CHAPTEE XL 
THE FEEDING OF PREMATURE INFANTS. 

In the Archives of Pediatrics, So. IT, 1900, James D. Voor- 
hees 216 has emphasized some of the most important points in 
the care of premature infants from his experience at the 
Sloane Maternity Hospital. 

Temperature. — This should he neither too low, which favors 
excessive heat radiation, nor too high, which increases cell 
metabolism. From 86° to 92° F. seems to be the correct 
average. 

Fresh Air. — The importance of this can be appreciated 
when Ave realize that the tissues of the nose and throat and 
mouth of the premature infant are extremely sensitive and 
unable to throw off infectious material conveyed by the dust. 

The infant should lie on a very soft pillow. Preliminary 
bathing should be avoided. If wrapped in cotton, this should 
not be placed directly next to the skin, but a light shirt and 
diaper should be first employed. The infant should not be 
disturbed to change the latter oftener than absolutely neces- 
sary. 

Feeding. — As a routine practice, within six hours after 
birth Voorhees begins by administering from one-half to one- 
drachm of a five to six per cent, lactose solution every hour. 
In from twenty-four to thirty-six hours he adds equal parts 
of breast-milk, preferably obtained from a wet-nurse who is 
from seven to eight days post-partum. The amount at each 
feeding is increased one drachm at a time until on the sev- 
enth day the baby is taking from six to eight drachms every 
hour. 

If the stools are normal, the proportion of milk can be in- 
creased and the sugar solution decreased. By adding a little 
270 



THE FEEDING OF PREMATURE INFANTS. 271 

lime-water, pure breast-milk can often be used at two weeks 
of age. The infant will usually nurse through a small nipple. 
In some cases we may have to make use of a medicine-dropper, 
and occasionally, when the infant is very weak or unable to 
swallow, garage is necessary. In the latter case, however, 
they seldom do well, as regurgitation is almost sure to occur. 
In this way the nasophanmx is filled, and on the next inspira- 
tion some of the fluid is drawn into the larynx and even into 
the bronchi. 

When the diet consists of pure breast-milk, the intervals 
should be gradually increased to two hours, so that by the time 
full term is reached the amount and interval will correspond 
to those of the normal infant. 

The results with diluted coVs milk are not nearly so satis- 
factory as with the above plan. 

Weight. — Premature infants lose considerably more in pro- 
portion to their birth weight than babies at term, and regain 
their original weight more slowly. Indeed, if this has been 
accomplished by the end of the second or third week they 
have done remarkably well. 

In regard to the use of the incubator, the general rule at 
the Sloane Maternity Hospital is to put the infant in cotton 
and surround it with hot-water bottles when its weight is near 
five pounds. If it does not thrive, or if the temperature falls, 
the incubator must be used. Those weighing four and a half 
pounds or less are put at once into the " couveuse." 

According to the statistics of Tarnier, Charles, and the 
Sloane Maternity Hospital: 

At six months of age from 10-16 per cent, are saved 

At six and a half months of age from 20-80 per cent, are saved 
At seven months of age from 40-49 per cent, are saved 

At seven and a half months of age from 75-77 per cent, are saved 
At eight months of age from 70-88 per cent, are saved 

Yaxderpoel Adriaxce. 184 The importance of proper feed- 
ing in cases of prematurity cannot be overestimated. In the 



272 THE ARTIFICIAL FEEDING OF INFANTS. 

first place, the gastro-intestinal tract is so poorly developed 
that fats and proteids are feebly digested. If modified milk 
is administered, it must be weak, not containing more than 
one per cent, of fat and 0.50 per cent, of proteids, until the 
alimentary tract is educated to its task. Modified milk is 
warmly recommended by Eotch, of Boston, but our experience 
indicates that it should not be used when proper breast-milk is 
available. 

Mother's milk is the ideal food, and every premature infant 
should have it if its variations and management are properly 
understood. The excess of proteids in colostrum milk is due 
to the sudden assumption of the mammary function. The 
breasts are unexpectedly engorged with an increased blood- 
supply and the mammary cells forced to activity. It is no 
marvel that during this strain the secreting cells permit of a 
serous transudation and that an excess of albumin is found 
in the secretion. 

The milk offered by the breasts during the first days after a 
premature labor is colostrum milk, and has its characteristics, 
but to an exaggerated degree. The marked increase in the 
amount of proteids is especially noticeable. The excess con- 
tinues longer, and it is not easily dispelled. It has even been 
found persisting as high as two per cent, in the second month. 
Analyses of Premature Milk at Successive Times. 

-n , „ , One month and 

Four days. Seventeen days. teQ d 

Per cent. Per cent. Per cent. 

Fat 3.39 3.32 3.33 

Carbohydrates 5.02 4.43 6.64 

Proteids 4.90 3.88 1.71 

Salts 0.31 0.26 0.10 

Total solids 13.66 11.91 11.79 

Water 86.32 88.08 88.20 

These analyses demonstrate an excessively high proteid per- 
centage, accompanied by a correspondingly high percentage of 



THE FEEDING OF PREMATURE INFANTS. 273 

salts. The amount of carbohydrates is lower than in any other 
series of milk analyzed. The management of this condition 
is difficult, since the milk of prematurity persistently main- 
tains this high percentage of proteids. It may be reduced by 
giving large quantities of water to the mother or by pumping 
the milk and diluting it with sugar of milk solution. Even if 
our efforts are successful, however, the milk presents different 
characteristics from that later in lactation and cannot be 
administered with safety. 

In cases of prematurity, then, a wet-nurse should be secured. 
Her infant must be healthy, full term, and two weeks of age 
(better, a month), in order that the characters of the colostrum 
period may be lost, and nothing will better determine the 
quality of her milk than its chemical examination. Meanwhile 
the secretion of the mother should be maintained by pumping 
and massage, so that it can be resorted to at the proper time. 

Cautley. 38 Hecker and Lusk give the following table, 
showing the weight of premature infants and the normal daily 
increase. 

At twenty-four weeks they should weigh 690 grammes; at 
twenty-eight weeks, 1170 grammes; at thirty-two weeks, 1560 
grammes; at thirty-six weeks, 1920 grammes; at thirty-eight 
weeks, 2310 grammes. During this time they should gain 
daily from 0.75 to one per cent, of their weight. 

Potel, from the investigation of three hundred and fifty 
cases, gives the following estimates: 

Age. Weight. Averag^ygainin 

Grammes. Grammes. 

Six and a half months 1400 9.4 

Seven months 1700 11.5 

Seven and a half months 1900 13.8 

Eight months 2150 22.8 

Of these three hundred and fifty cases nearly fifty per cent, 
survived. The gastric capacity may be roughly estimated at 

18 



274 THE ARTIFICIAL FEEDING OF INFANTS. 

one per cent, of the body weight. In modifying milk to suit 
these cases we use the same constituents, simply reducing the 
percentage of solids. 

Eotch gives the following formulas: Formula I. At from 
twenty-eight to thirty-six weeks, proteids 0.5 per cent., fat 
one per cent., sugar three per cent. If the infant is not satis- 
fied, or if the child is unusually large, or when it is thirty 
weeks old, we may give Formula II. : proteids 0.5 per cent., 
fat 1.5 per cent., sugar four per cent. If the infant is over 
thirty-two weeks old, give Formula III. : proteids 0.75 per 
cent., fat 1.5 per cent., sugar five per cent. 

Give twenty-four meals a day: of Formula I. four cubic 
centimetres each, heated to 75° C; of Formula II. eight cubic 
centimetres each, heated to 75° C; of Formula III. twelve 
cubic centimetres each, heated to 75° C. If the infant is over 
thirty-six weeks old, give Formula IV. : proteids one per cent., 
fat two per cent., sugar 5.5 per cent. Give twenty-four meals 
a day, of sixteen cubic centimetres each, heated to 75° C. 

If the infant cannot digest these mixtures, try condensed 
milk or a mixture of egg albumin, water, cream, and sugar. 
Saw meat juice must also be given. It is better to feed fre- 
quently and in small quantities than to risk causing dilatation 
of the stomach and gastro-enteric disorders by giving larger 
quantities less frequently. 

If the child is thriving, we can gradually increase the inter- 
vals until at term it takes normal amounts at normal intervals. 
If the infant is too weak to nurse, special apparatus has to be 
employed which will force food into its mouth, or gavage must 
be resorted to. 

Ashbt and Wright. 2 It is probably best to draw off the 
mother's milk, dilute it, and feed the premature infant through 
a pipette. Failing in this, sterilized whey may be used, diluted 
with water if necessary. Give from two to four drachms every 
hour. 



CHAPTER XII. 
PBINCIPLES OF INFANT FEEDING. 

Whex we survey the various methods which have been ad- 
vocated in different parts of the world for the artificial feeding 
of infants, we encounter wide differences of opinion. 

In England, France, Germany, and Austria the prevailing 
tendency is to feed the infant on milk mixtures containing 
high proteid percentages. Milk diluted one-third or equally 
with water, and sweetened, is considered the proper food for 
a healthy babe during the first months of life; this diet is 
continued until at the age of eight or nine months whole milk 
is given. Although there is a rather low fat percentage in 
such mixtures, those who advocate this method of feeding 
do not consider that it is necessary to remedy the deficit in 
fat by the addition of cream ; some of them advise the addition 
of an excess of sugar to take the place of the fat. Sterilization 
of the milk is considered practically indispensable by most 
French and German pediatrists. 

Attempts have been made by Heubner and others to base the 
food requirements of the infant on the number of calories 
daily consumed, taking as a basis the number of heat units 
furnished by definite quantities of mother's milk (the compo- 
sition of the latter being assumed to be fairly constant) . But 
when we consider how markedly the needs of different infants 
vary, depending on their rate of growth, strength, digestive 
capacity, etc., it seems certainly more advisable to follow broad 
practical lines in the regulation of their diet than to estimate 
their food requirements according to strictly scientific prin- 
ciples. 

275 



276 THE ARTIFICIAL FEEDING OF INFANTS. 

The majority of leading American writers and teachers em- 
phasize the necessity for greater dilution of cow's milk to ren- 
der it easy of assimilation by the young infant. They advise 
to begin the administration of cow's milk by diluting it three 
or four times with water, gradually increasing the strength 
of the milk mixture until the end of the first year or later, 
when whole milk can usually be given without harm. To 
compensate for the low percentage of fat which results from 
high dilution of milk, the addition of small quantities of cream 
to the milk mixture is advised, while the percentage of sugar 
is increased by the addition of milk-sugar until it equals 
six or seven per cent., the proportion present in mother's 
milk. 

When the process of sterilization was introduced, American 
plrysicians were among the first to recognize its importance 
and the necessity for its employment under certain conditions 
and at certain times of the year, to render milk fit for the 
infant's use. They were equally prompt to note the advantages 
of pasteurization; the latter method of heating milk soon 
came into general use in America, while it is only of late years 
that much notice of it has been taken by Continental authori- 
ties. 

Unquestionably the greatest step in advance in recent years 
towards the successful hand feeding of infants has been the 
discovery that it is possible to produce practically pure sterile 
milk, and thus dispense with sterilization altogether in pre- 
paring the child's food. To Henry L. Coit, of Newark, belongs 
the credit of having demonstrated the fact to the American pro- 
fession and to the public at large that pure so-called " certified 
milk" could be obtained by instituting proper Irygienic pre- 
cautions regulating the production and care of the milk. 
" Certified milk" can now be obtained in quite a number of 
our large cities. Its price is necessarily higher than that of 
ordinary milk, but it seems probable that, when the public 
becomes sufficiently alive to the importance of obtaining clean 



PRINCIPLES OF INFANT FEEDING. 277 

milk, competition will reduce its cost and bring it within the 
reach of all. Sterilization and pasteurization will then become 
of minor importance. 

As Baginsky has well said, the chief requisite for success 
in the management of the infant's diet is the ability to make a 
thorough study of the needs of the individual case and to treat 
the child accordingly. Since no two children have identical 
food requirements, the physician who can correctly determine 
the qualitative composition of the food — that is, the relative 
proportion of the different ingredients suited to the particular 
case — will be more successful than he who prescribes a definite 
quantity of a food which, theoretically or on scientific grounds, 
the infant should be able to digest. 

For the convenience of the reader it has seemed advisable 
to classify the various methods advocated for the feeding of 
healthy infants before discussing in detail the principles in- 
volved. 

I. Whole Milk. — Some pediatrists, most of them French, 
contend that whole cow's milk, provided it has been sterilized, 
can safely be administered even to the youngest infant. This 
view has not found general favor in this country. It is con- 
trary to the great mass of clinical evidence, which has taught 
us that the majority of healthy infants cannot properly digest 
pure cow's milk until near the end of the first year. Undoubt- 
edly there are numerous exceptions to this rule. Czerny and 
Schlesinger have called attention to the fact that in some cases 
of malnutrition from improper feeding nothing is so satisfac- 
tory as the administration of small amounts of whole milk at 
long intervals (from three to five hours). No doubt many 
of these cases had previously been fed on excessive amounts 
of highly diluted milk mixtures which did not contain enough 
nourishment to meet the demands of the organism. When 
excessive quantities of water are given in this way for long 
periods of time, we fail to supply the necessary physiological 
stimulus to the gastric secretions, we interfere with digestion 



278 THE ARTIFICIAL FEEDING OF INFANTS. 

by dilution of the gastro-intestinal juices, and we run serious 
risk of causing dilatation of the walls of the already enfeebled 
stomach. We must therefore not lose sight of the fact that 
in a certain class of cases it may be expedient to resort to a 
diet of whole milk long before the child, from the theoretical 
stand-point, could be expected to digest it. 

II. Modeeate Dilutions (i.e., High Proteids). — Many 
pediatrists advise plain dilutions of milk with water or barley- 
water with sugar added. Heubner, Marfan, and Koplik are 
prominent advocates of this method of feeding, which is based 
on the conviction that the healthy infant can digest, even at an 
early age, a mixture containing two parts of milk and one of 
the diluent (the so-called Heubner-Hoffmann Mixture). Aver- 
age milk diluted one-third will contain about two and a half 
per cent, proteids and from two to two and a half per cent, 
fat. Enough lactose should be added to make the proportion 
of sugar seven per cent. Undoubtedly many infants will thrive 
on this mixture, which has at least the advantage of simplicity 
of preparation to recommend it. When we consider, though, 
the frequency with which cases of indigestion and malnutrition 
are encountered among infants who have been fed during the 
first months of life on milk so slightly diluted, we must recog- 
nize that a very large proportion, even of healthy infants, can- 
not digest and assimilate the Heubner-Hoffmann Mixture at 
this period. The high proteid content of this mixture con- 
stitutes the chief difficulty for the digestion of the young in- 
fant; at a later period of life (six months and over) the low 
fat content will be an objection. 

III. High Dilutions (i.e., Low Proteids). — Biedert, John 
Forsyth Meigs, and Jacobi were the first to uphold the doc- 
trine that cow's milk should be diluted for the young infant 
three or four times with water until the proportion of proteids 
is reduced to about one per cent, (milk one part, water three 
parts, give proteids one per cent., fat from three-quarters to 
one per cent.). They arrived at this conclusion as the result 



PRINCIPLES OF INFANT FEEDING. 279 

of their clinical observation before the amount of casein in 
mother's milk had been accurately determined. (The idea of 
adding cream to the milk mixtures to supply the deficit of 
fat caused by dilution seems to have originated with Biedert 
abroad and with the elder Meigs in this country.) Undoubt- 
edly the administration of high dilutions of milk with cream 
and sugar added is one of the most widely applicable and most 
serviceable methods of infant feeding. 

IV. Top-Milk Mixtures.— Instead of adding cream to di- 
lutions of milk and water, dilutions of top milk may be em- 
ployed. It is convenient to denominate as "top milk" the 
upper layers of milk which has stood for a sufficient length of 
time (from twelve to twenty-four hours) to allow the gravity 
cream to rise to the surface. 

V. Whey Mixtures. — Monti, of Vienna, is the principal 
advocate of the use of whey and milk mixtures for healthy 
infants. Whey may be added to either milk or cream. The 
advantages of such mixtures are obvious. We can give almost 
any desired proportion of casein and fat together with the 
easily digested whey-proteids. Such mixtures are especially 
adapted for difficult cases in which the digestion of casein is 
at fault. 

VI. Laboratory Milk. — The introduction of the Milk- 
Laboratory is the work of T. M. Rotch, of Boston, and repre- 
sents one of the latest advances in the scientific feeding of 
infants. The great advantage of Laboratory Milk is that we 
can be sure of the exact composition of the milk food we are 
giving. We are able to call in our prescriptions for any de- 
sired percentage of the different ingredients and can practi- 
cally eliminate the danger of the milk becoming contaminated 
before it reaches the consumer. 

One objection has been raised against Laboratory Milk pre- 
pared with centrifugal cream, — namely, that the natural con- 
dition of the elements of the milk is replaced by an artificial 
combination of these elements; to accomplish this, the milk 



280 THE ARTIFICIAL FEEDING OF INFANTS. 

is first separated into a solution of proteids (fat-free) and a 
solution of cream with low proteids, and then reeombined. 
It is an open question whether the physical and chemical 
characteristics of the milk (the state of the emulsion of the 
fat-molecules) are not affected by such manipulations so as 
to render Laboratory Milk more difficult of absorption and 
assimilation; in other words, we may question whether the 
milk has not lost, to some extent at least, its vital character- 
istics. However this may be, the clinical experience with Labo- 
ratory Milk of such well-known pediatrists as Jacobi, Starr, 
and Koplik has been of such a character as to modify the 
enthusiasm with which this product was first received. On 
the other hand, Eotch, Holt, Northrup, and many other com- 
petent observers are firm believers in the value of Laboratory 
Milk. The advocates of this method of feeding can find no 
proof that the emulsion of the fat is in any way affected by 
the manipulations in the laboratory. We may perhaps best 
summarize the situation by stating that Laboratory Milk repre- 
sents a great advance in modern methods of feeding; it is 
successful in a large proportion of cases when sufficient ex- 
perience with its proper application has been gained, but it 
fails in a certain percentage of cases, even in the best hands. 
Intelligent home modification of milk still remains our chief 
resource for the feeding of the great majority of infants, since 
the expense of the laboratory product puts it out of the reach 
of all but the well-to-do. 

One great advantage of the Milk-Laboratory to the com- 
munity consists in the fact that it furnishes a pure product 
of known and definite composition. The standard required 
for Walker-Gordon milk has already served to excite competi- 
tion among milk dealers and has increased the supply of milk 
suitable for the purposes of infant feeding. It has also drawn 
the attention of the public to the necessity for hygienic regu- 
lations controlling the purity of such a universally used food 
as cow's milk. 



PRINCIPLES OF INFANT FEEDING. 281 

Under these six headings we have outlined the principal 
methods in nse at the present day for the feeding of healthy 
infants. Before deciding what plan we should adopt, we 
must consider what are the food requirements of the indi- 
vidual infant. This we know to be a variable factor depending 
on the child's age, weight, rate of growth, degree of muscular 
development, etc, The previous methods of feeding, and the 
existence of gastro-intestinal catarrh due to improper selection 
of the child's food, must also be taken into account when we 
are estimating the infant's actual powers of digestion. 

The regulation of the quantity of food to be given at each 
feeding and the interval between meals is of equal importance 
with the decision what the child's food shall be. Those who 
advocate high proteid mixtures believe that the infant digests 
casein slowly ; they therefore prolong the pauses between feed- 
ings to three hours or even longer for dyspeptic as well as 
healthy infants. They believe that small quantities of milk 
mixtures containing high proteid percentages will be better 
tolerated than weaker mixtures containing an excess of water. 
On the other hand, those who believe in greater dilution of 
the milk consider that it is better to feed at shorter intervals 
(from two to three hours), taking care not to give the child 
an amount of fluid in excess of the gastric capacity. Some- 
times a failure to gain in weight, in the absence of dyspeptic 
symptoms, shows the necessity of increasing the total quantity 
of food without altering the strength of the mixture, in order 
to re-establish the nutritive equilibrium. 

The tables of Holt, Eotch, and Pfaundler (Chapter IV.) 
should be consulted in order to determine the average capacity 
of the stomach at different periods of infancy. 

The child's age is a good general guide on which to base 
the amount of food required, but it must not be forgotten that 
there are many children in whom increase in gastric capacity 
does not run parallel with the gain in age or the increase in 
weight; in these cases the gain in body length may serve as a 



282 THE ARTIFICIAL FEEDING OF INFANTS. 

guide (Pfaundler). Careful clinical observation will, how- 
ever, rarely fail to determine correctly what quantity of food 
the infant is capable of digesting successfully. 

We must next decide what proportions of the different ele- 
ments of milk are best adapted to the infant's needs. Perhaps 
the most important question is, How much proteid or nitroge- 
nous food shall we give? 

Proteids: Casein and Albumin. 

In spite of the teachings of Heubner, Czerny, and others, 
and the metabolism experiments of Keller, Heubner, and 
Bendix, which seem to prove the contrary, the statement must 
be reiterated that the chief obstacle to success in the hand 
feeding of infants consists in the difficulty in digestion of the 
casein in cow's milk. The differences in the behavior of 
mother's milk casein and cow's milk casein, when introduced 
into the infant's digestive tract, are well known. The former 
coagulates in small, soft, homogeneous masses which are readily 
penetrated by the gastro-intestinal juices and are easily re- 
dissolved, while the latter forms large, tough, irregular curds 
which are difficult of solution and are often passed only par- 
tially digested through the intestinal tract. Moreover, we 
must emphasize the fact that mother's milk and cow's milk 
are two distinct fluids adapted physiologically to widely differ- 
ent purposes, and that the digestive powers of the babe in 
arms and those of the calf are very unequal factors. 

Since no amount of modification, however scientific, can 
render cow's milk exactly like mother's milk, it is well to 
dismiss from our minds the idea that all we have to do is 
"to imitate maternal conditions." This is especially true 
of the early months of life, when great and irreparable dam- 
age to the infant's digestion frequently follows and is the direct 
result of faulty methods of feeding. Suppose an infant three 
or four weeks old were taken from the breast and given a 
milk mixture imitating in composition the natural secretion 



PRINCIPLES OF INFANT FEEDING. 283 

at this period of lactation. We would then constitute the 
child's food as follows: proteids from one and three-quarters 
to two per cent., fat from three to four per cent., sugar six 
per cent., and salts 0.2 per cent. Certainly there are not many 
infants, even if we include those with unusually well-developed 
powers of digestion, who are capable of digesting a mixture of 
this composition without harm at this period of life. Therefore, 
when we have to feed infants on cow's milk, the essential to 
success is that the child's g astro-intestinal tract be gradually 
accustomed to the digestion of cow's milk casein. If the first 
steps in this process of education are correctly carried out, 
the infant will soon acquire the power to digest relatively 
large amounts of cow's milk proteids. Should the first steps 
be wrong, however, incalculable injury will result which may 
take months or even years to remedy. 

As a general rule, when we first administer cow's milk to 
the infant, it is well to reduce the proteids to rather low pro- 
portions (one per cent, or less). If this is necessary when we 
are weaning the breast-fed child who is nine months or one 
year old, it becomes imperative when we have to feed an infant 
under three months of age for whom the maternal nourish- 
ment has failed. In such a case our choice will usually lie 
between two methods. Either we may reduce the proportion 
of casein in cow's milk by dilution until a percentage is reached 
which the child is able to digest (this will vary from one 
per cent, for healthy infants during the first month to as low 
as 0.50 per cent, or even 0.25 per cent, for the new-born and 
those who are delicate or have weak digestions), or as an 
alternative we may use peptonized milk, modified by the ad- 
dition of cream and diluents. The advantage of this method 
of feeding is that it enables us to give the infant a larger 
amount of proteids than he would be able to digest in the 
raw state. For a new-born infant the proportions of our 
peptonized milk mixture should be about one per cent, pro- 
teids, from two to two and a half per cent, fat, and six per 



284 THE ARTIFICIAL FEEDING OF INFANTS. 

cent, sugar. If this is well tolerated, the strength of the 
mixture may be increased to one and a half per cent, proteids, 
three per cent, fat, and six per cent, sugar at the end of the 
fifth or sixth week. If it is desirable to continue this mode of 
feeding during the third and fourth months, the proportions 
may be increased to proteids two per cent., fat three and a half 
per cent., and sugar seven per cent. 

It must be understood that peptonization is only a temporary 
expedient, and that it is inadvisable, except for difficult cases, 
to continue the process over a longer period than two or three 
months. By gradually reducing the time of peptonization, 
there will seldom be any difficulty in replacing this food with 
a milk mixture containing the same proportions. It is well 
known that the most critical period in the life of the arti- 
ficially fed infant is the first three months. During this time, 
therefore, the proportion of casein in the infant's diet (unless 
it is peptonized) should rarely exceed one per cent. By be- 
ginning with low proportions of casein and gradually in- 
creasing the proteid strength of the mixture we can accustom 
the child to its digestion, so that the average healthy infant 
in fair hygienic surroundings will thrive at the age of six 
months on a mixture containing from one and a half to two 
per cent, proteids, and at the age of from twelve to sixteen 
months will be able to take whole milk. 

Delicate infants with weak digestion, cases of malnutrition, 
and the like generally require dilute mixtures with low pro- 
teids. For them we must increase the proteid percentages 
slowly and cautiously, since they cannot digest the proportions 
of proteids suitable for healthy infants until a much later 
period of life. 

There are some infants who seem unable to digest more than 
minimal amounts of cow's milk proteids and fats, so that any 
attempt to increase the strength of the milk mixture in order 
to maintain the proper nutritional equilibrium is followed 
by gastro-intestinal disturbances. In these cases we must 



PRINCIPLES OF INFANT FEEDING. - 285 

resort to peptonized milk, whey-cream mixtures, egg albumin, 
beef juice, meat broths, dextrinized attenuants, etc.; or we 
may use such preparations as Steffen's veal broth, Gregor's 
malt soup, or somatose milk. Pure buttermilk is said to be suc- 
cessful in a certain proportion of cases (see page 113). When 
the infant's digestion has regained to some degree its normal 
powers, we should again try to feed the child on plain mixtures 
of milk and cream. Exceptionally we meet cases in which 
even such mixtures are not tolerated before the end of denti- 
tion; the selection of the proper food then becomes a problem 
of great difficulty. 

Fat. 

The fat of cow's milk, like the casein, is less easily assimi- 
lated than the same ingredient in mother's milk. It stands 
next to casein in difficulty of digestion. We know (see Chapter 
IV.) that there is always an excess of fat excreted in the 
faeces, and that this condition may become pathologically ex- 
aggerated until actual enteritis results (Biedert's fat diar- 
rhoea). In deciding, then, what percentage of fat must be 
given in the infant's food, we must bear in mind that moder- 
ate rather than high percentages usually give the best results. 
Two per cent, of fat may safely be administered to the new- 
born child, and the percentage may be soon increased to three, 
provided the infant is healthy and has a vigorous digestion. 
During the first four or five months of the child's life it is 
rarely necessary to reduce the percentage of fat below two, 
and rarely advisable to exceed the limit of three and a half. 
In some cases it is permissible to increase the proportion of 
fat to four per cent, during the second half of the first year; 
for the great majority of infants, however, the limit of three 
and a half per cent, of fat had best not be exceeded until the 
child is put on a diet of whole milk. 

It is evident, then, in considering the question, How much 
fat does the infant require? that we are unable to imitate 
very closely maternal conditions. While the healthy breast- 



286 THE ARTIFICIAL FEEDING OF INFANTS. 

fed infant can digest and assimilate large amounts of fat 
(four per cent, and over), even in the first months of life, 
the bottle-fed baby can rarely take with advantage more than 
three per cent, of fat at the same period; sometimes even this 
amount will not be tolerated. 

The success with which some babies are raised on a diet 
of condensed milk or cow's milk simply diluted with water 
would seem to indicate that certain children thrive, for a time 
at least, on low fat percentages. Such cases must be the 
exceptions, however. They often show subsequently signs of 
improper nutrition (rickets, anasmia, scurvy, excessive fat 
deposits, etc.). The rapidly growing organism requires a 
plentiful supply of fuel, which is furnished it in the hydro- 
carbons and carbohydrates, while the larger part of the nitro- 
gen serves to build up the rapidly growing muscular system. 
The starches and fats thus diminish the consumption of ni- 
trogen, and may be considered " nitrogen-savers." 

The proportion of the nitrogenous to the non-nitrogenous 
elements in the infant's diet is a matter of great importance. 
We must not overlook the fact that the average ratio of these 
elements in the child's natural food (the breast-milk) is about 
one nitrogenous to seven and a half non-nitrogenous, whereas 
in cow's milk the average ratio is about one of the former 
to two and a half of the latter. In a rough way we may 
estimate that mother's milk contains twice as much fat as 
proteids and four times as much sugar. On the other hand, 
cow's milk, when undiluted, contains almost equal propor- 
tions of proteids, fat, and sugar; hence the non-nitrogenous 
elements constitute not much more than twice the nitrogenous, 
whereas the "nitrogen-savers" of mother's milk exceed the 
nitrogen-carrying elements more than seven times. The im- 
portance, therefore, of a sufficient supply of fat and sugar 
for the proper growth of the infant can scarcely be over- 
estimated, since that child will thrive best in whose diet the 
different food elements properly balance one another. Yet 



PRINCIPLES OF INFANT FEEDING. 287 

some authorities on children's diseases still recommend plain 
dilutions of milk with water which neither satisfy the normal 
requirements of the infant nor allow full play for its meta- 
bolic activities. 

We may supply the deficiency in fat caused by dilution 
in either of two ways: by adding fat directly to the milk 
mixture in the shape of cream or by making use of top milk 
which contains a fairly large proportion of gravity cream. 
In the former case we may follow the method in vogue at 
the Walker- Gordon Milk-Laboratory, where a small amount 
of centrifugal cream with high fat (and low proteid, sugar, 
and salt) percentage is added to separated milk (a solution 
containing proteids, sugar, and salts, but almost no fat) ; in 
other words, we mix two solutions, one with high fat and 
the other with high proteid content, to obtain the percentages 
we desire; or we can add cream to whole milk, according to 
some of the formulae devised by Westcott, Baner, and others 
(see Chapter XIII.). If we use top milk, we dilute our pro- 
teids and fat at the same time, and the calculation is sim- 
plified. The great advantages to be gained from the use of 
top milk are that the natural emulsion of the fat is in no 
way disturbed, and that the same relative proportions of 
proteids to fat obtain which are found in mother's milk, — 
namely, the amount of fat is twice or three times that of 
the proteids. The objections which may be made to top milk 
are twofold. First, it may be urged that there is great lia- 
bility to error in calculating the fat percentage, unless fre- 
quent analyses of the milk are made. Secondly, since the 
milk must stand for a long time (from twelve to twenty-four 
hours) before the gravity cream will come to the surface, it 
will almost certainly be infected by the bacteria which rise 
with the cream. It will be shown in the next chapter that 
the first objection may prove a serious one. The danger of 
bacterial contamination will be slight if we can obtain "cer- 
tified" or equally pure milk, bottled at the dairy and kept below 



288 THE ARTIFICIAL FEEDING OF INFANTS. 

45° F. till it is used: if desired, this milk may be pasteurized 
immediately after milking. 

must not forget that ordinary commercial cream is 
more often than not u nfi t for the infant's use. Centrifugal 
cream has the advantage of being fresh; it is still open to 
question, however, whether the mechanical disturbance caused 
by separation does not affect its digestibility and absorbability. 

Sugar. 

Sugar is the only carbohydrate normally present in milk. 
It seems probable that the lactose in cow's mil k is not identical 
with that of mothers milk. This difference of composition 
is of less consequence for the infant than the differences in 
the fat and the proteids. since milk-sugar causes serious di- 
gestive disturbances much less frequently than either of the 
other constituents of milk. The majority of pediatrists use 
lactose, the natural sugar of milk, for the purposes of infant 
feeding, although some competent observers consider cane- 
sugar preferable. Maltose is recommended by Keller. During 
the first weeks of life and for sick or delicate infants the 
proportion of sugar in the milk mixture should not exceed 
five per cent. Later this can be increased to six or seven per 
cent. If there are digestive disturbances, the quantity of sagai 
must be reduced. When the ad min istration of starchy foods 
is begun, the proportion of sugar need not exceed that found 
in whole milk . — about 1.5 per cent. It is important that a 
pure preparation of milk-sugar be used. Holt advises that it 
be dissolved in boiling water ; it must be prepared freshly each 
day and filtered through absorbent cotton before it is used, to 
remove accidental impurities. 

Salts. 
The percentage of salts present in milk mixtures is usually 
disregarded, since it is considered that their proportion will 
not be reduced below that of mothers milk bv anv ordinarv 



PRINCIPLES OF INFANT FEEDING. 289 

degree of dilution. It is true that the salts of cow's milk 
exceed those in mother's milk over three times; so that we 
may dilute cow's milk to this extent and still have about the 
same proportion of mineral matters as is present in mother's 
milk. It would seem, however, from Blauberg's careful study of 
the faeces in connection with Heubner's metabolism experiments, 
that the salts of cow's milk (undiluted) are not so well assimi- 
lated as those of mother's milk, and that it is doubtful whether 
dilution of the milk compensates for this difference. Moreover, 
the amount of sodium chloride in cow's milk is alread}' less 
than that in mother's milk; hence the importance of adding 
salt to the infant's food, a point to which Jacobi has long 
since drawn our attention. It seems probable, too, that the 
breast-fed infant can assimilate phosphorus more completely 
than the artificially nourished child, since much of this min- 
eral is present in the breast-milk in organic combinations 
which seem to be more readily absorbed. 

The amount of calcium salts in cow's milk is half again 
as great as that in mother's milk; but when we dilute cow's 
milk two or three times, the proportion of lime salts falls 
decidedly below that present in mother's milk. The same holds 
true of the phosphates, provided any considerable degree of 
dilution is practised. In the present state of our knowledge, 
it is impossible to decide absolutely as to the importance of 
these salts in the infant's metabolism. 

Staech. 

Most authorities favor the use of decoctions of cereals as 
diluents, believing that this facilitates the digestion of casein, 
besides adding slightly to the nutritive value of the milk mix- 
ture. Undoubtedly there are some infants who cannot digest 
any form of starch until dentition is well advanced, but it is 
equally true that a larger number are decidedly benefited by 
this addition to their food. In some cases starch proves to 
be of distinct advantage as a tissue-saver, since it checks 

19 



290 THE ARTIFICIAL FEEDING OF INFANTS. 

albuminous waste. Again, the use of a starchy decoction 
before the administration of the milk mixture often seems 
materially to aid in the digestion of the proteids, particularly 
when there is a tendency to gastric intolerance of proteids 
due to rapid curdling (Holt). When the administration of 
carbohydrate food is indicated before the period of dentition, 
the starch may be dextrinized, since it is more easily digested 
in this form and possesses greater nutritive value. In some 
of the best infant foods on the market practically all of the 
starch is dextrinized ; they can, therefore, be used as adjuvants 
to milk when the administration of starch is indicated. 

Whey. 

Monti deserves credit for calling attention to the importance 
of whey as a diluent for cow's milk. The whey-proteids are 
easily digested ; they resemble the soluble albumins of mother's 
milk in their physical and chemical properties, and the re- 
placing of a portion of the casein of cow's milk by soluble 
albumin in this form has proved of decided value for the 
infant's nutrition. 

The amount of soluble albumin in cow's milk is estimated 
to be about 0.50 per cent., while the total whey-proteids aver- 
age from 0.80 to one per cent. Thus it appears that these 
whey-proteids comprise not only the soluble albumin in cow's 
milk, but also a portion of the casein which has been converted 
into a soluble form by the action of rennin. By the use of 
whey instead of water as a diluent we can materially increase 
the proportion of whey-proteids in our milk mixture and 
avoid the administration of large amounts of casein. Whey 
may be mixed with milk, top milk, or cream in any desired 
percentage, or it may be given alone to premature or weak in- 
fants; it is particularly valuable as a means of beginning the 
administration of milk after an acute attack of indigestion. 
Whey-cream mixtures yield a much finer coagulum than plain 
milk and cream mixtures with the same proteid content. 



PRINCIPLES OF INFANT FEEDING. 291 

Peptonized Milk. 

The indications for the use of peptonized milk have already 
been given. Milk and cream may be mixed in any desired 
proportion and the process of peptonization can be carried out 
for from ten minutes to half an hour or longer. It requires 
about two hours to completely peptonize milk. The use of pre- 
digested milk offers disadvantages in that this food does not 
furnish the necessary physiological stimulus to the infant's 
stomach, since it is offered already prepared for intestinal 
digestion and absorption. Where the milk is only partially 
peptonized, this objection has less weight. It is well to begin 
with half an hour's peptonization, gradually reducing the 
time as the infant's digestive powers regain their normal con- 
dition. 

Egg Albumin. 

Ever since the investigations of Lehmann showed the pres- 
ence of soluble albumin in mother's milk various methods have 
been devised to provide a substitute for this easily digestible 
constituent. Hesse was the first to use egg albumin in his 
infant food. Now there are various preparations on the mar- 
ket which base their claims to be perfect substitutes for the 
maternal nourishment on the presence of a certain amount 
of white of egg. Apart from the question of its digestibility, 
there seems to be some reasonable doubt whether egg albumin 
is sufficiently well assimilated to aid very materially the in- 
fant's nutrition. At the same time it serves a useful purpose 
at certain critical periods when the administration of milk 
in any form is contraindicated. Egg albumin may be given 
either mixed with water and a little salt or added to various 
decoctions of starch, meat broths, etc. It is probably inferior 
to whey in nutritive value. 

Beep Juice, Broths, Peptonoids. 
Usually these preparations are not added to the infant's 
diet till the time of weaning or at the end of the first year. 



292 THE ARTIFICIAL FEEDING OF INFANTS. 

Before this time they may be used during attacks of milk 
infection, or as accessories to the diet in cases of anaemia, 
rickets, etc. When the child is unable to digest large amounts 
of casein, beef juice and broths often prove of great service, 
since they furnish proteids and salts in readily assimilable 
form. When diarrhoea exists, mutton broth is preferable to 
veal or beef broth. The concentrated foods, such as the liquid 
peptonoids, panopepton, etc., prove of distinct value during 
gastro-intestinal affections when all milk must be withheld. 
The small proportions of alcohol they contain especially com- 
mend them in those cases where there is marked constitu- 
tional depression. 

Lime-Water. 

The addition of lime-water to cow's milk is generally con- 
sidered to be the best means of reducing the acidity of the 
latter. The greater acidity of cow's milk as compared with 
mother's milk is a point on which much stress has been laid; 
but this is purely a relative matter, depending on the care 
and cleanliness observed in the handling of the milk, the 
number of lactic and other acid-producing bacteria present, 
and the temperature at which the milk is kept before it reaches 
the consumer. The amount of lime-water required is variously 
estimated at from one-twentieth to one-fourth the total quan- 
tity of the mixture. For " certified milk" the proportion of 
one-twentieth will be sufficient, but if any marked degree of 
acidity is present in the milk, it will be necessary to use larger 
quantities to attain our purpose. 

The use of lime-water as a routine practice seems hardly 
necessary when the infant's digestion is healthy and the milk 
supplied in a fresh condition. If the milk mixture is steril- 
ized by heat, lime-water must be added subsequently. 

Weight. 
To ascertain whether or not the child is thriving the prac- 
titioner has no single guide of greater value than the informa- 



PRINCIPLES OF INFANT FEEDING. 293 

tion obtained by weighing the infant at weekly intervals. 
Roughly stated, a healthy child should gain from six to seven 
ounces a week during the first three months, from four to five 
ounces a week between the fifth and the seventh months, and 
from two to three ounces a week between the ninth and the 
twelfth months. During the second year the rate of gain is 
approximately from one and a half to two ounces a week. 

Of course many children gain irregularly in weight, more 
especially those who are artificially fed on an ill-assorted 
variety of food. Again, a child may increase rapidly in weight 
during one week and make little or no gain the next, and still 
be in good health. However, we may assume that a fairly 
constant rate of gain is the normal condition of the infant, 
any marked departure from which indicates disturbance of 
nutrition, which, again, is due in the great majority of in- 
stances to faulty methods of feeding. 

Sterilization and Pasteurization. 

A question which will infallibly present itself to the prac- 
titioner concerning the preparation of the milk mixture is 
whether it will be necessary to apply heat to guard against the 
danger of milk infection. Our decision will be based on the 
condition of the milk when it reaches the consumer. If we 
are able to obtain pure milk which can be kept cold before and 
after it reaches the consumer, and if there is little or no dan- 
ger of its contamination during the process of preparing the 
infant's food, it will be unnecessary to employ any method of 
pasteurization or sterilization, at least during the cool months 
of the year. 

When contamination of the milk has already occurred or is 
likely to occur during the handling it undergoes on the part 
of the mother or nurse, it becomes almost indispensable to 
apply heat in some form or other. The degree of heat neces- 
sary to destroy the bacteria present in milk has been the sub- 
ject of much debate. It is almost impossible to reconcile the 



294 THE ARTIFICIAL FEEDING OF INFANTS. 

many conflicting statements. We must remember, though, 
that many of these assertions are not based on the results 
of original research, but are copied from the work of other 
investigators, often without corroboration of the methods em- 
ployed. More extended observation and more perfect knowl- 
edge of the life-conditions of the different species of bacteria 
will be required before we can advocate definite degrees of 
temperature for their destruction with absolute certainty of 
success. We must also not lose sight of the importance of the 
unorganized ferments present in milk; since they play a role 
in the digestive process, their destruction by heat cannot be 
regarded as immaterial for the child's welfare. In this field 
we have probably still much to learn. 

From the evidence at hand, without being able to add the 
results of original investigations, we have attempted to specify 
what we may expect to accomplish by the application of heat, 
allowing a certain range in the degree of heat to be used to com- 
pensate for possible errors. Heating from 60° to 68° C. (140° 
to 155° F.) for thirty minutes (the milk being kept in closed 
bottles to prevent the formation of a pellicle on the surface) 
will destroy or render innocuous the tubercle bacilli and the 
common pathogenic germs, such as those of diphtheria and 
scarlet fever. It will also destroy the majority of the lactic- 
acid-producing bacteria. This temperature will not destroy the 
spore-bearing butyric and peptonizing bacteria and other va- 
rieties which under certain conditions may produce lactic acid. 
From 70° C. (158° F.) up the unorganized ferments will be 
destroyed and the milk will begin to undergo certain chemical 
and physical alterations which probably render it less easily 
digested and assimilated. 

It is important to remember that when we use a low tem- 
perature (60° C.) the skim or pellicle which forms on milk 
heated in uncovered vessels will protect the bacteria it encloses 
in its meshes and prevent their destruction. Heat should there- 
fore always be applied to the milk in closed vessels, or the milk 



PRINCIPLES OF INFANT FEEDING. 295 

should be kept thoroughly mixed by agitation during the 
process of heating. If we wish to destroy all the lactic-acid- 
producing bacteria, the temperature to be employed should be 
not less than 75° C. (167° F.) for from twenty to thirty 
minutes. 

When the milk supplied is highly contaminated, it must be 
sterilized at 100° C. (212° F.) for at least thirty minutes. 
If it is not possible to preserve the milk at a low temperature, 
more especially during hot weather when bacteria multiply so 
rapidly, it will be safer to repeat the process of heating every 
six hours. Whatever disadvantages this degree of heat may 
entail are more than offset by the advantage of destroying all 
the bacteria with which the milk is infected. Such milk, even 
after sterilization, should not be employed for the infant's use 
unless milk of a better quality cannot be obtained; for we 
know that the spores of the peptonizing bacteria are not de- 
stroyed even by temperatures as high as 110° C. ; and should 
conditions favorable for their development be present, the pep- 
tonizing bacteria may multiply in apparently sterile milk and 
prove a grave source of danger for the infant. 



CHAPTEE XIII. 
METHODS FOR THE HOME MODIFICATION OF MILK. 

There are two methods of procedure available for the physi- 
cian who proposes to feed a child with milk modified at the 
home. Either he may prepare and modify his mixture accord- 
ing to the clinical evidence afforded by the state of the child's 
digestion and nutrition, disregarding the percentages of the 
ingredients, or he may begin by the administration of a formula 
representing the percentages of fat, sugar, and proteids suitable 
for a given age and weight, altering them at will as the needs 
of the case demand, but always having at least an approximate 
idea of the strength of the food administered. The first method 
is empirical and easy of execution; the latter is quite as suc- 
cessful and much more satisfactory. A good example of the 
former method is the mixture of John Forsyth Meigs, con- 
sisting of equal parts of barley-water, lime-water, milk, and 
cream, sweetened. We know that it contains about two per 
cent, of proteids and four per cent, of fat, and we can vary 
the proportions of the different ingredients from time to time 
to meet the clinical indications. Success in infant feeding, 
then, depends quite as much on the ability to correctly inter- 
pret clinical phenomena as on the selection of the method, pro- 
vided the plan of feeding adopted be not too rigid to allow for 
the wide variations in the digestive capacity of the infant. 

In order to make even the simplest calculations we must be 
familiar with the percentages of the different ingredients in 
whole milk. It is safe to assume that milk of good quality 
will contain from three and a half to four per cent, proteids, 
four per cent, fat, four and a half per cent, sugar, and 0.7 per 
cent, salts.* The average milk supplied in cities will contain a 
lower proportion of fat than the above, varying from three to 

* See page 326. 
296 



HOME MODIFICATION OF MILK. 297 

four per cent. The simplest method of feeding is to dilute 
milk with water or barley-water and add sugar; examples of 
this are Biedert's milk formulae and the Heubner-Hoffmann 
Mixture. To ascertain the strength of our milk mixture we 
divide the percentages of the different ingredients by the degree 
of dilution employed. If we add two parts of water to one of 
milk, we dilute the milk three times and must divide by three ; 
one part of milk to three of water gives us a divisor of four, 
etc. The simplest method for the estimation of sugar is to 
ascertain what percentage of lactose must be added to compen- 
sate for the degree of dilution and to make a sugar solution 
containing this percentage. For instance, if we dilute good 
milk four times, our mixture will contain about one per cent, 
proteids, one per cent, fat, and one per cent, sugar. To pro- 
vide six per cent, sugar in the food we therefore use a five 
per cent, sugar solution for our diluent, made by dissolving 
one ounce of sugar (lactose) in twenty ounces of water. To 
provide seven per cent, sugar a six per cent, solution of lac- 
tose is made by adding one ounce of lactose to sixteen and 
two-thirds, ounces of water. For practical purposes we may 
estimate that three level tablespoonfuls of milk-sugar equal 
one ounce, and one and a half even teaspoonfuls equal one 
drachm. If we use granulated sugar, two level tablespoonfuls 
equal one ounce and one even teaspoonful equals one drachm. 
For greater accuracy receptacles of known capacity must be 
procured. The addition of starchy decoctions, such as barley-, 
rice-, or oatmeal-water, adds very small amounts of proteids 
and fat and about one and a half per cent, of starch to the 
mixture. The sugar solution may be made with such decoc- 
tions instead of plain water. Enough must be prepared each 
morning to supply the total quantity needed during the day; 
during the summer months it will be safer to prepare our sugar 
solution twice a day to insure its freshness. 

Since it is impossible by simple dilution of milk to obtain 
at the same time a sufficiently low proportion of proteids and 



298 THE ARTIFICIAL FEEDING OF INFANTS. 

a sufficiently high proportion of fat, it becomes necessary to 
add fat to the diet for the great majority of cases. Cream 
resembles the fat of mother's milk more closely than any other 
substitute (such as butter, cod-liver oil, etc.), and since it is 
also, when fresh, more readily digestible than these other 
forms of fat, it should be employed for the purposes of infant 
feeding. The use of cream is associated with manifest objec- 
tions. It is almost sure to be contaminated with bacteria, — 
in commercial gravity cream bacterial decomposition may be 
well advanced during the summer months, — it is very com- 
monly adulterated by " cream thickener" or, worse, by preserv- 
atives, and, finally, the percentage of butter fat can rarely be 
known 'with accuracy. The importance of obtaining cream that 
is fresh and clean can scarcely be overestimated. During the 
hot weather of our American summers even the best cream 
sours very readily. Unless we can obtain it from a thoroughly 
reliable dealer, and unless we can be sure that it will be kept 
at a sufficiently low temperature (from 45° to 50° F.) until 
it is used, it is better to discard the use of cream altogether 
during the summer months. Whenever possible, the physician 
should acquaint himself personally with the methods in use at 
the dairy from which the milk and cream for the infant's diet 
are procured, since it is only thus that he can make sure that 
the cream is fit for use (unless he can obtain " certified milk"). 
During the summer months he should employ only freshly 
centrifugated cream, or gravity cream which has been cooled 
immediately after milking and kept below 50° F. during the 
time it is raising. 

There still remains to be decided the question: How much 
fat is present in the cream we are using ? Chapin's and Holt's 
tables give us estimates of the cream in top milk and will be 
discussed later. We have no means of knowing the exact per- 
centage of fat in ordinary gravity or centrifugal cream, unless 
the dealer is willing to furnish a fat analysis. Commercial 
cream usually contains from twelve to sixteen per cent, of 



HOME MODIFICATION OF MILK. 299 

butter fat; this variation is so great that it renders accuracy 
in the calculation of formulae impossible. If we wish to know 
exactly how much fat we are giving the child, analysis of the 
cream becomes indispensable. Eight per cent., twelve per cent., 
and sixteen per cent, cream may be used in preparing our mix- 
tures, also centrifugal cream containing still higher fat per- 
centages. The higher the proportion of fat the lower will be the 
proportion of the other ingredients. 

The following table has been used as a basis for making 
various formulae, such as Westcott's, Bauer's, etc. In his latest 
edition Holt states that the figures for the proteids are too 
high (see page 131). 

Fat. Proteids. Sugar. Salts. 

Per cent. Per cent. Per cent. Per cent. 
Whole milk or four per cent, cream 

gives 4 4.00 4.50 0.70 

Eight per cent, cream gives 8 4.00 4.40 0.70 

Twelve per cent, cream gives 12 3.80 4.20 0.64 

Sixteen per cent, cream gives 16 3.60 4.00 0.60 

Twenty per cent, cream gives 20 3.20 3.80 0.55 

Thirty-two per cent, cream gives 32 2.80 3.20 (?) 0.40 (?) 

By simple dilution of cream with a sugar solution of the 
desired strength we can prepare various mixtures of high fat 
content. For instance, by mixing one part of twelve per cent. 
cream and three parts of water we get: fat three per cent., 
proteids 0.90 per cent., sugar 1 per cent., and salts 0.15 per 
cent. The sugar-water should then be of five per cent, strength 
to give a total of six per cent, in our mixture. By mixing one 
part of eight per cent, cream with three parts of five per cent, 
sugar solution we get : fat two per cent., proteids one per cent., 
sugar six and one-tenth per cent., and salts 0.17 per cent. An 
eight per cent, cream can be obtained by mixing one part of six- 
teen per cent, gravity cream and two parts of whole milk, or 
one part of twenty per cent, centrifugal cream and three parts 



300 THE ARTIFICIAL FEEDING OF INFANTS. 

of whole milk. A twelve per cent, cream can be made by 
mixing two parts of sixteen per cent, gravity cream and one 
part of whole milk, or equal parts of twenty per cent, centrifu- 
gal cream and wjiole milk (Holt). 

These simple dilutions of cream with sugar solution are easy 
to prepare and will prove serviceable in many cases. We may 
raise one objection to them, — namely, that the proportion of 
fat and proteids must be increased and decreased together, 
since the ratio of fat to proteids, using eight per cent, and 
twelve per cent, cream, must be either two to one or three to 
one. To meet this objection we must employ either milk or 
whey in preparing our mixtures. Egg albumin has not proved 
a satisfactory substitute for the proteids of milk, except as a 
temporary expedient in cases of digestive disturbance when all 
milk must be withheld. 

Various mathematical formulae have been devised for esti- 
mating the quantity of whole milk and cream required to give 
us definite milk formulae. The first of these was published by 
Thompson S. Westcott, of Philadelphia, in January, 1898; 
following this, in March, 1898, William L. Baner, and in May, 
1898, Henry L. Coit published their methods. In March, 1899, 
F. Lewis Taylor generalized the previous calculations; "his 
formulae must be accepted as the groundwork of every system 
of calculation for percentage formulae" (Westcott). Shriner 
has also devised a method of calculating percentages similar 
to that in use at the Walker-Gordon Laboratory. Henry L. 
Coit, in the Archives of Pediatrics for May, 1898, describes 
his method for the home modification of cow's milk, using a 
decinormal cream solution for the fat, a saccharated skimmed 
milk solution for the proteids not in the cream, and a standard 
sugar solution for the lactose not in either of the above. The 
practical application of this method is difficult. 

Bauer's formulae for the home modification of milk, pub- 
lished in the New York Medical Journal, March 12, 1898, are 
simple and easily remembered. 



HOME MODIFICATION OF MILK. 301 

Given : 

The quantity desired in ounces Q 

The desired percentage of fat F 

The desired percentage of sugar S 

The desired percentage of proteids P 

To find (in ounces) : 

Cream (16 per cent. ) = 5. X (F — P) 



Milk. 



QXP 



4 
Water = Q — (C + M) 

Lactose = (S^P)_XQ 

100 

Tf 20 per cent, centrifugal cream were used, the denominator would 
be 16. 

If 12 per cent, were used, it would he 8. 

Example. — To provide twenty-four ounces of a mixture con- 
taining one per cent, proteids, three per cent, fat, and six per 
cent, sugar : 

94 

Cream (16 per cent. ) = — X (3 — 1) = 2X 2 = 4 ounces 

Milk = 24X ] — 4 =6 — 4 = 2 ounces 

4 

Diluent = 24 — (4 -f 2) = 24 — 6 == 18 ounces 

a (6 — 1) X 24 5 X 24 ,. 
Suffar = A z_Z^ — = _/\ — _ — 11 ounces 

5 100 100 

Thompson" S. Westcott, 197 in an elaborate monograph on 
the scientific modification of milk, published in International 
Clinics, October, 1900, has considered at some length the 
question of milk modification by mathematical formulae. We 
have selected only those which are adapted to general use, and 
must refer the reader to the original article for more extensive 
knowledge on the subject. 

To determine the quantities of cream, milk, lactose, and 



302 THE ARTIFICIAL FEEDING OF INFANTS. 

water for a given formula : C = cream, M = milk, F = fat, 
P = proteids, L = lactose, T = total quantity, S = sugar per- 
centage desired. 

c = (g-P)Q 

8.2 (12 <f c cream) or 12.4 (16 f cream) or 16.8 (20 <f cream) 
M = SI _ 3 c (12 f c ) or 4 C (16 f c ) or 5 C (20 f c ) 

QS— 4.3(M-f C) 
100 

If twenty ounces of a mixture be desired, containing three 
per cent, fat, six per cent, sugar, and two per cent, proteids, 
using sixteen per cent, cream, the formula would read : 



c- 


.(8-2) 

12.4 


20 _ 20 _ 
12.4 


1.5 


ounces 








M = 


_20X3 
4 


-4X 1.6 = 


_60 

" 4 


— 6 = 


9 ounces 




T,- 


_ 20 X 6 - 


-4.3 (9+1 


.6). 


120- 


-45_ 


- 3 
4 


ounce 



Conversely, in order to determine the percentage of ingredients 
in any combination of cream, milk, and sugar, Westcott sug- 
gests the following : 

To find percentage of fat : 

Q 

— X 16 (or 12) = fat percentage from cream 

Q 

M 

— X 4 = fat percentage from milk 



Sum of these = total fat percentage in mixture 

To find percentage of proteids : 

C 

— X 3.6 (16 <fc ) or 3.8 (12 <jf c ) = proteid percentage from cream 

Q 

M 

— X 4 = proteid percentage from milk 

_Q 

Sum of these = total proteid percentage in mixture 

c , 100L + 4.3 (M + C) 
Sugar percentage = ! * ! / 



HOME MODIFICATION OF MILK. 303 

For instance, taking the same mixture as above determined, — 
namely, one and a half ounces of sixteen per cent, cream, nine 
ounces of milk, three-quarters of an ounce of lactose, and nine- 
teen and a half ounces of water : 



¥>< 16 = 


= 1.2 










9 X 

2b" x 


4 = 


= L8 
3.0 per cent. 


total fat 








20 X 


3.6 = 


= .27 










-^X 
20 X 

100 x 


4=1.80 

2.07 per cent, total proteids 
.75 + 4.3 X 10.5 _ 75 + 45.15 _ g 


per 


cent. 


sugar 



20 

Westcott has also published formulae for mixtures of sepa- 
rated milk and centrifugal cream. Unless we wish to obtain 
either very low or very high fat percentages, mixtures of cream 
and whole milk are all that is necessary. 

Edward Hamilton, in the American Journal of Obstetrics, 
October, 1901, 250 describes a method based on the fact that 
ordinary cream, milk, and skimmed milk contain relatively the 
same amount of proteids and salts, and that cream is simply 
a superfatted milk. If we multiply the quantity of milk mix- 
ture to be used by the percentage of fat desired and divide by 
the percentage of fat in the cream used, we obtain the amount 
of cream; if we multiply the quantity of milk mixture by the 
percentage of proteids desired, divide by four (the percentage 
of proteids in skimmed milk), and subtract from this result 
the amount of cream previously determined, we obtain the 
amount of skimmed milk needed. The quantity of the milk 
mixture less the amount of cream and skimmed milk will equal 
the amount of the diluent to be used. Three drachms (one 
level tablespoonful) of lactose must be added to each ten ounces 
of the mixture ; lime-water or soda may be used to reduce the 
acidity. 



304 THE ARTIFICIAL FEEDING OF INFANTS. 

Example. — Forty ounces of mixture desired: fat four per 
cent., sugar seven per cent., proteids two per cent, (sixteen per 
cent, cream to be used) . 

40 X 4 -r- 16 = 10 ounces cream 
40 X 2 -r- 4 = 20 — 10 = 10 ounces of skimmed milk 
40 — 20 = 20 ounces diluent 
Sugar = four level tablespoonfuls 
Lime-water q.s. 
This method seems to be an adaptation of Bauer's formula, 
using skimmed milk in place of whole milk. 

The advantages of adding whey to milk or cream mixtures 
have already been considered. We are enabled to combine the 
digestible whey-proteids with the proteids and fat of cream or 
milk, thereby greatly lowering the proportion of coagulable to 
non-coagulable proteids. 

Practically, three methods may be employed in the prepara- 
tion of whey. 

1. Simple coagulation with rennet or essence of pepsin, 
avoiding subsequent agitation of the curd, the fluid being 
allowed to separate solely by gravity. Whey so prepared will 
contain practically all the salts and sugar of the milk, a mini- 
mum of casein, a small amount of fat, and all of the soluble 
albumin (Monti). Its composition may be estimated at: 
whey-proteids from 0.85 to one per cent., fat 0.33 to 0.50 per 
cent., sugar 4.50 per cent., salts 0.18 per cent. 

2. After coagulation the curd may be thoroughly beaten until 
disintegrated and the fluid contents expressed by straining 
forcibly through several layers of cheese-cloth. This is again 
strained to remove the fine casein flakes which were forced 
through. This preparation will contain more fat (perhaps as 
much as one per cent.) and slightly more casein than whey 
separated by the preceding method. 

3. Like the second method, except that the casein flakes are 
not strained. A small amount of casein may thus be adminis- 
tered in a readily assimilable form. 



HOME MODIFICATION OF MILK. 305 

An objection to the use of whey is the expense of preparing 
it, but if we remove the top milk from a quart bottle, we can 
usually obtain enough whey from what remains for the purpose 
of dilution. Before adding whey to cream or milk, it should 
be heated to 65° C. (150° F.) in order to destroy the rennet 
enzyme. At 70° C. (160° F.) the soluble albumin begins to 
coagulate. 

Eotch says that it is cheaper to prepare whey from fat-free 
milk. 

Konig^s analysis of whey (proteids 0.86 per cent., fat 0.32 
per cent., sugar 4.79 per cent., salts 0.15 per cent.) was used 
by Westcott in preparing the following tables of whey-cream 
mixtures. Other authorities have found as high as one per 
cent, of whey-proteids, while Honti asserts that whey contains 
as high as one per cent. fat. This percentage of fat is probably 
obtained bv a method similar to Xo. 2. 



Quantity of c-mto^u^a twenty-ounce J fo givg ^ ^^ 

Per cent. Per cent. 
Twenty per cent, cream. 

0.70 ounce 1.00 0.94 

1.71 ounces 2.00 1.06 

2.72 ounces 3.00 1.18 

3.74 ounces 4.00 1.30 

Sixteen per cent, cream. 

0.87 ounce 1.00 0.98 

2.14 ounces 2.00 1.15 

3.42 ounces 3.00 1.32 

4.69 ounces 4.00 1.50 

Twelve per cent, cream. 

1.16 ounces 1.00 1.03 

2.88 ounces 2.00 1.28 

4.59 ounces 3.00 1.53 

6.30 ounces 4.00 1.79 

20 



306 THE ARTIFICIAL FEEDING OF INFANTS. 

Eight per cent, cream. 

1.77 ounces 1.00 1.13 

4.38 ounces 2.00 1.53 

6.98 ounces 3.00 1.92 

9.58 ounces 4.00 2.32 

Four per cent, cream (whole milk). 

3.69 ounces 1.00 1.44 

9.13 ounces 2.00 2.29 

14.56 ounces 3.00 3.15 

20.00 ounces 4.00 4.00 

The only objection to the use of such tables is that they can 
scarcely be memorized and may not be available when needed. 
The simplest method of determining the proportions in a whey- 
cream mixture is to add the percentages of the different ingre- 
dients, dilute with plain water or barley-water, and divide by 
the degree of dilution. 



Sixteen per cent, cream (one part) 

Whey (one part) 

Water ( three parts ) 

Total (five parts) = 16.50 4.60 8.50 0.78 

Diluting with three parts of water and dividing by five, we 
get a mixture composed as follows : fat 3.3 per cent., proteids 
0.92 per cent., sugar 1.70 per centi, and salts 0.15 per cent. 
We must then add enough sugar to our mixture to bring the 
sugar percentage up to six or seven. For instance, if we wish 
to prepare a whey- cream mixture containing 0.92 per cent, 
proteids, 3.3 per cent, fat, 0.15 per cent, salts, and six per 
cent, sugar, we must dilute with a seven per cent, sugar solu- 
tion. The amount of sugar present in the cream will then be 
represented by four, that in the whey by 4.5, and that in three 



Fat. 


Proteids. 


Sugar. 


Salts. 


Per cent. 


Per cent. 


Per cent. 


Per cent. 


16.00 


3.60 


4.00 


0.60 


0.50 


1.00 


4.50 


0.18 



HOME MODIFICATION OF MILK. 307 

parts of seven per cent, sugar solution by twenty-one (3 X 7 = 
21). Adding these figures, we obtain 29.50, which must be 
divided by the degree of dilution (five) to give us the amount 
of sugar present, — almost six per cent. 

Another method of bringing up the sugar percentage to the 
desired strength is simply to add sugar to the total quantity of 
the mixture. For example, twenty-five ounces of the above 
mixture, when prepared with plain water, will contain 1.7 per 
cent, sugar. By adding one ounce of lactose to twenty-five 
ounces of water we increase the sugar percentage of our mixture 
by four (4 -|- 1.7 = 5.7 per cent, sugar). 

To prepare two ounces of a whey-cream mixture containing 
1.5 per cent, proteids, 1.5 per cent, fat, and five per cent, sugar, 
add two drachms of eight per cent, cream to fourteen drachms 
of whey. We thus dilute our cream eight times, and must 
divide by eight to obtain the percentage of fat, proteids, and 
sugar represented by the cream. 



Cream (eight per cent.) contains 

Whey contains 

Total 1.50 1.50 5.00 

In a recent publication 254 Thompson S. Westcott presents 
new formulae for the preparation of whey, cream, and whole 
milk mixtures. In the newer method the proportions of casein 
and lactalbumin can be altered at will. He has adopted Van 
Slyke's figures of four to one for the proportion of caseinogen 
to lactalbumin {Journal of the American Chemical Society, 
November, 1893, p. 605) ; lactalbumin therefore equals one- 
quarter casein. Westcott estimates on the basis of one per 
cent, whey-proteids in whey (Wisconsin Agricultural Experi- 
ment Station). The significance of the symbols used in the 
formulae is as follows: 



Fat. 


Proteids. 


Sugar. 


Per cent. 


Per cent. 


Per cent. 


) 8.00 


4.00 


4.00 


1.00 


0.50 


0.50 


0.50 


1.00 


4.50 



308 THE ARTIFICIAL FEEDING OF INFANTS. 

F = desired fat percentage 

K == desired casein percentage 

A = desired lactalbumin percentage 

S = desired sugar percentage 

W = desired diluent 

C = quantity of cream in ounces 

M = quantity of milk in ounces 

"Wh = quantity of whey in ounces 

L = quantity of dry lactose in ounces 

Q = total quantity of mixture 

P' = percentage of combined proteids supplied by milk and cream 

A / = percentage of lactalbumin supplied by whey 

Therefore, P' = K -f £ K 

and A' = A-|K 

Having found the value of A / , the quantity of whey is easily calculated 
by the proportion : 

A' : 1.00 : : Wh : Q 

Whence Wh = — XQor Wh = A' X Q 

1.00 

Example. — Kequired a mixture of forty ounces containing 
fat three per cent, casein 0.80 per cent., lactalbumin 0.50 per 
cent., sugar six per cent, (sixteen per cent, cream to be used). 

P' =.80 +.20=1.00 
A' =.50— .20= .30 
. •. Wh = .30 X 40 = 12 ounces 

By substituting in his regular formula (page 302) the value of P' 
instead of P, we obtain : 

C = (8.50 -LOO) 40 = 8ounces 
12.4 
and 

M= 3.50 X 40_ 4><8= 3ounces 
4 

W = 40 — (8 + 3 + 12) = 17 ounces 



HOME MODIFICATION OF MILK. 309 

The amount of lactose is determined by the formula : 

L _ Q X S — (4 C 4- 4.4 M + 4.8 Wh) 

_ 100 

40x 6— (4X8 + 4.4 X 3 + 4.8X 12) 13 
. •. L == ^ i — ^ — ^ -^ — — ^ L = If ounces 

100 8 

Ordinarily sixteen per cent, cream will furnish sufficient 
fat; rarely twenty per cent, cream will be needed. The pro- 
portion of lactalbumin can never exceed one per cent, and will 
practically always fall below this. The range of variation of 
the casein, lactalbumin, and fat has been calculated for dif- 
ferent strengths of cream. In the main they may be stated as 
follows : from one to four per cent, fat, from 0.07 to 3.20 per 
cent, casein, and from 0.017 to 0.95 per cent, lactalbumin. 

Conversely, to determine the proportions of fat, casein, and 
lactalbumin in a given mixture, we may use the following : 

For fat percentage : 

C 

— X (16 or 20 or 32) == fat percentage from cream 

Q 

— X 4 = fat percentage from milk 

Sum of these = fat percentage in the modification 

For caseinogen percentage : 

C 4 

— X (3.6 or 3.2 or 2.8) X - = caseinogen percentage from cream 
Q 5 

— X 4 X - = caseinogen percentage from milk 

Q 5 

Sum of these = caseinogen percentage in the modification 

For lactalbumin percentage : 

C 1 

X (3.6 or 3.2 or 2.8) X:^ lactalbumin percentage from cream 

Q ' 5 

M 1 

X 4 X ~ = lactalbumin percentage from milk 

Q 5 

Wh 

XI = lactalbumin percentage from whey 

Q * 

Sum of these = lactalbumin percentage in modification 

g = 100 L + 4 C -f- 4.4 M + 4.8 Wh 

Q 

Note. — W^estcott includes all the " whey-proteids" under the heading 
" lactalbumin." 



310 



THE ARTIFICIAL FEEDING OF INFANTS. 



Top-Milk Mixtures. 

Chapin's method was described in the New York Medical 
Journal, February 23, 1901, and may be summarized as fol- 
lows: 

The results of a large number of analyses of top milk by 
the Babcock method enable us to divide milk into three classes, 
the poor, the medium, and the rich, in which the percentages 
of fat average three, four, and five respectively. When bottled 
milk is allowed to stand undisturbed, most of the cream will 
rise within from sixteen to twenty hours; the fat in the 
skimmed milk will vary from 0.5 to 1.5 per cent. 

Chapnr's table represents the varying percentages of fat in 
the upper sixteen ounces of a quart bottle of milk which has 
stood for at least twelve hours. 



Fat in whole milk 


3 pc 


r cent. 


4 per cent. 


5 per cent. 


Fat in skimmed milk .... 


0.5 


1.0 1.5 


0.5 


1.0 


1.5 


0.5 


1.0 1.5 


Fat in top six ounces 


13.8 


11.6 9.5 


19.1 


17.0 


14.8 


24.5 


22.3 20.1 


Fat in top seven ounces . . 


11.9 


10.1 8.3 


16.5 


14.7 


12.9 


21.0 19.4 17.5 


Fat in top eight ounces . . . 


10.5 


9.0 7.5 


14.5 


13.0 


11.5 


18.5 


17.0 15.5 


Fat in top nine ounces . . . 


9.5 


8.1 6.8 


12.9 


11.7 


10.4 


16.5 


15.2 14.0 


Fat in top ten ounces .... 


8.6 


7.4 6.3 


11.7 


10.6 


9.5 


14.9 


13.8 12.7 


Fat in top eleven ounces . . 


7.8 


6.8 5.9 


10.7 


9.7 


8.8 


13.6 


12.6 11.7 


Fat in top twelve ounces. . 


7.2 


6.3 5.5 


9.8 


9.0 


8.1 


12.5 


11.7 10.8 


Fat in top thirteen ounces 


6.7 


6.0 5.2 


9.1 


8.4 


7.6 


11.6 


10.8 10.1 


Fat in top fourteen ounces 


6.3 


5.6 5.0 


8.5 


7.8 


7.2 


10.7 


10.1 9.5 


Fat in top fifteen ounces . . 


5.9 


5.3 4.7 


8.0 


7.4 


6.8 


10.1 


9.5 9.0 


Fat in top sixteen ounces . 


5.5 


5.0 4.5 


7.5 


7.0 


6.5 


9.5 


9.0 8.5 



If Chapin's method is to be used, and it is impossible to 
obtain analyses of the fat in the whole milk and skimmed milk, 
the physician must be content with approximate percentages: 
accuracy is out of the question. The market milk furnished 
by the smaller dealers to the poorer classes probably rarely 



HOME MODIFICATION OF MILK. 311 

exceeds the legal limit of three per cent. fat. The milk from 
the better class of dairies will contain as much as fonr per 
cent, fat or even higher. The high-grade product of Alderney 
and Jersey cattle will often eqnal fonr and a half or five per 
cent. 

Assuming then, for example, that we can obtain a medium 
milk, and taking the middle column of Chapin's medium milk 
table as the safest average, we then divide this figure by the 
degree of dilution employed in order to obtain the percentage 
of fat in our mixture. We assume, for facility in calculation, 
that the percentages of proteids and sugar in our cream are 
four each (actually they are somewhat lower in cream of high 
fat percentage). For instance, the upper nine ounces of me- 
dium milk (middle column) contain 11.7 per cent, fat, four 
per cent, sugar, and four per cent, proteids. To prepare thirty- 
six ounces for the day's supply we add to these nine ounces 
twenty-seven ounces of a five per cent, sugar solution, thus 
diluting the top milk four times ; dividing by four, we get this 
result: fat 2.92 per cent., proteids one per cent., and sugar 
one per cent, plus five per cent, (in the diluent) equals six 
per cent. If we mix the upper ten ounces of medium milk 
(middle column) with twenty ounces of a five per cent, sugar 
solution, and divide the percentages by three, our mixture will 
contain: fat 3.53 per cent., proteids 1.33 per cent., and sugar 
1.33 per cent, plus five per cent, (in the diluent) equals 6.33 
per cent. 

To make four per cent, sugar solution add one ounce of lac- 
tose to twenty-five ounces of water; to make five per cent, 
sugar solution add one ounce of lactose to twenty ounces of 
water; to make six per cent, sugar solution add one ounce of 
lactose to sixteen and two-thirds ounces of water. 

Chapin has devised a dipper of one ounce capacity which can 
easily be inserted into the neck of the ordinary quart milk- 
bottle. The obvious advantages of this method are that the 
consumer obtains a product in which the dangers of contamina- 



312 THE ARTIFICIAL FEEDING OF INFANTS. 

tion from handling are reduced to a minimum, that the neces- 
sity for employing commercial cream is avoided, and that the 
cream and milk in our mixture are obtained from the same 
source. 

In order to test more fully the range of variations of the 
fat in top milk, the authors decided to obtain a number of 
analyses of the product of a single first-class dairy. 

It seemed reasonable to suppose that the variations would 
be less than those found in Chapin's experiments with milk 
from different sources. The results, however, showed that in 
a whole milk with a fat percentage varying from five to 5.5 
the amounts of fat in the upper ounces showed in many in- 
stances as great or greater variations than Chapin's figures 
indicate. Without daily tests absolute accuracy is therefore 
impossible with top-milk mixtures. 

When we consider, however, the frequent and decided varia- 
tions in the fat content which occur in mother's milk without 
harm to the healthy infant, it seems probable that moderate 
variations in the fat content in a cow's milk mixture, when 
the child has become accustomed to the digestion of cow's milk, 
will probably rarely lead to digestive disturbances, provided 
the milk is pure and the child is carefully fed. 

The tests we have made fairly establish a working average 
for the milk of one dairy during a certain period (from Janu- 
ary to March). We hope to continue them during the re- 
mainder of the year, and also to establish a ratio between the 
fat in the whole milk and the fat in the top milk in the same 
bottle. When this ratio has been determined, an occasional 
test of the whole milk will show whether the proper propor- 
tion of fat is being maintained. 

The tests were made for us by Mr. Walter Cuthbert, a grad- 
uate in chemistry, whom we were fortunate enough to interest 
in this subject. He controls in large part the output of the 
Spotswood Dairy Farm at Broad Axe, Pennsylvania. 

The whole-milk tests show a uniformly high percentage of 



HOME MODIFICATION OF MILK. 313 

fat; the uppermost ounces from such a milk are therefore not 
available for infant feeding, as any reasonable dilution of the 
fat would bring the proteid percentage much below what is 
needed. This difficulty could be obviated by dilution with 
skimmed milk or whole milk, using the top milk only as a 
rich cream. As one of the primary objects of the top-milk 
method is to obtain the fat and proteids from the same supply, 
it is better to remove the upper ten ounces or more even if this 
entire amount is not needed. The larger amounts will also 
contain practically all the fat from that quart, and the varia- 
tions will depend on the amount of fat in the whole milk, while 
the proportion of this ingredient in the upper two to six ounces 
depends also on the length of time the cream has been raising, 
the temperature, physical condition of the fat-globules, etc. 
For these reasons our tests have mainly been made with the 
larger amounts of top milk. 

In making the fat tests Mr. Cuthbert employed the Leff- 
mann-Beam method described on page 342. The quart bottles 
were selected entirely by chance. The cream had been raising 
from fourteen to sixteen hours and the cream layer was there- 
fore fully formed. 

In removing the top milk we employed a cone-shaped dipper 
constructed according to J. C. Gittings's design by V. Clad & 
Sons. The cone-shaped base permits the dipper to pass easily 
through the cream layer without disturbing it. 




The first ounce was partially removed by pouring into the 
dipper, which could then be inserted without causing the cream 
to overflow. It was a noticeable fact that the actual measure- 
ment of the cream layer in all the bottles tested varied only 
from 3.4 to four inches. The depth of this layer depends on 



314 



THE ARTIFICIAL FEEDING OF IXFAXTS. 



the shape of the bottle, the length of time the cream has been 
raising, and the temperature. The first two conditions being 
the same in all onr tests, we found the following variations 
dependent on the weather conditions, irrespective of the fact 
that the milk was kept well iced. 

Weather conditions. Inches ° f ?\ e ™ iu one 

quart bottle. 

Moderate and warm 3. 70 average 

Moderate and freezing 3.75 to 4.00 

Continuous freezing: 4.00 average 



Table of Fat Percentages in Top Milk. 



Whole 
milk. 


Upper six- 
teen ounces. 


Fourteen 
ounces. 


Twelve 
ounces. 


Ten 
ounces. 


Eight 
ounces. 


5.0 


9.6 


10.2 


12.3 


14.4 


18.6 


5.0 


9.6 


10.5 


12.6 


14.4 


18.9 


5.0 


9.6 


10.8 


13.2 


14.4 


19.2 


5.1 


9.6 


10.8 


13.2 


15.0 


19.8 


5.1 


9.6 


10.8 


13.2 


15.0 


19.8 


5.1 


9.9 


11.4 


13.5 


15.0 


20.1 


5.2 


10.2 


11.4 


13.5 


15.6 




5.2 


10.2 


11.7 


13.5 


15.6 






5.2 


10.2 


11.7 


13.6 


15.6 






5.3 


10.2 


11.7 


13.8 


15.9 






5.3 


10.4 


11.8 


13.8 


16.2 






5.3 


10.5 


12.0 


13.8 


16.2 






5.4 


10.5 


12.0 


13.8 


16.2 






5.4 


10.8 


12.0 


13.8 


16.8 






5.4 


10.8 


12.0 


14.1 


17.1 






5.4 




13.2 










5.5 




13.2 










Average. 


Average. 


Average. 


Average. 


Average. A 


verage. 


5.23 


10.11 


11.6 


13.44 


15.56 


19.- 


to 



six 
ounces. 

21.6 

21.6 
22.5 
22.8 



Four 
ounces. 

23.4 

23.7 

24.3 

24.3 



Average. 
22.12 



Average. 

23.92 



HOME MODIFICATION OF MILK. 315 

As we will have to dilute the top milk at least three times, 
the possible error in the fat percentage of our mixture, ac- 
cording to this table, will be reduced by this dilution so as 
to fall below 0.5, — rarely as high as this. For example, the 
column of fat values for the upper fourteen ounces shows the 
greatest variations, — from 10.2 to 13.2. If we divide the aver- 
age of tliis column (11.6) by 3 we get 3.9 fat. The possible 
error will therefore be : 10.2 -r- 3 = 3.4 and 13.2 -r- 3 = 4.4, 
figures respectively .5 above and .5 below the average. Although 
this is far from strict accuracy, it is probably less of an objec- 
tion than might be supposed. 

Condensed Milk. 

No preparation of cow's milk enjoys a wider popularity 
among the laity, especially among the poorer classes, than con- 
densed milk. Few physicians of wide experience have failed 
to note that many infants have not only lived but thrived upon 
an exclusive diet of condensed milk during the early months 
of life. Condensed milk must be well diluted before it is given 
to the infant. If we add to it from eight to twelve times its 
amount of water, we reduce its proteid and fat content to one 
per cent, and less, while the proportion of sugar becomes from 
five to six per cent. This amount of sugar is sufficient, but the 
proportion of proteids and fat is too low, especially the latter. 

One possible explanation for the child's apparent thriving 
and gain in weight is that a " teaspoonful" of the condensed 
milk is in reality almost two teaspoonfuls, since almost as much 
of the thick syrupy milk adheres to the bottom and edges of the 
spoon as the spoon contains. We actually, then, administer 
an excess of sugar, a proper proportion of proteids, and a 
deficient amount of fat; the sugar can be converted into fat 
and give the child its plump appearance ; the proteids are pre- 
sented in an easily digestible form, since they clot in much 
finer curds than raw cow's milk; while the fat, being in fine 
emulsion, is also usually well utilized. Clinical observation 



316 THE ARTIFICIAL FEEDING OF INFANTS. 

has proved^ however, that a prolonged exclusive diet of con- 
densed milk often results in the development of such nutri- 
tional disorders as anaemia, rickets, scurvy, and athrepsia. 
Moreover, the infant, while apparently healthy, lacks vital 
resistance and easily succumbs to the various infectious diseases 
which he may contract. The deficiency in fat, the excess of 
sugar, and the " lack of freshness'' in condensed milk are 
probably all causative factors in these results. 

There is no doubt that the judicious employment of con- 
densed milk meets certain indications in infant feeding, — 
namely, where persistent, intelligent modifications of cow's 
milk have failed, and where lack of resources or of intelligent 
co-operation on the part of the mother prevents the adoption of 
more elaborate methods of feeding. As a temporary expedient, 
condensed milk may be administered for short periods of time 
to tide over emergencies, especially among the poor during the 
summer months, when it is difficult to obtain good milk and to 
keep it from spoiling. 

Whenever possible, we should attempt to supplement the 
inherent deficiencies in a condensed milk diet by the addition 
of fresh cream. With such supplement the infant undoubtedly 
will receive sufficient nourishment to meet the demands of the 
organism, even for long periods of time, though it should always 
be our aim to revert to a diet of cow's milk as soon as oppor- 
tunity offers. It is important to select those brands of con- 
densed milk which contain high fat percentages (some as high 
as twelve per cent.) and to use only those which are preserved 
by the addition of cane-sugar. The following formulae, based 
on Holt 5 s analysis of Eagle Brand Condensed Milk, are given 
as examples of what percentages may be obtained with mixtures 
of condensed milk and cream. 

When we desire to increase the proteid percentage without 
appreciably increasing the fat, we can use whey to replace a 
portion of the water in the diluent, taking care not to increase 
the sugar excessively. 



HOME MODIFICATION OF MILK. 



317 





Proteids 
Per cent 


Fat. 
Per cent. 


Sugar. 
Per cent. 


Salts. 
Per cent. 


I. 


Cream (twelve per cent.) one part. 3.8 


12.00 


4.2 


0.64 




Condensed milk one part 8.4 


7.00 


50.00 


1.39 




Water six parts 










8)12.2 


19.00 


54.2 


2.03 




Average 1.5 


2.5 


6.75 


0.25 

Per cent. 


II. 


Cream (sixteen per cent.) one part. 

Condensed milk one part 

Water six parts 


■ = ■ 


r Proteids 
Pat 

Sugar. . 
L Salts... 




1.5 
3.00 
6.75 
0.25 


III. 


Cream (sixteen per cent.) one part. 

Condensed milk one part 

Water ten parts 


■ = « 


' Proteids 
Fat 

Sugar . 
. Salts... 




1.00 
2.00 
4.5 






0.16 



By employing cream of higher fat percentage the proportion 
of fat can be increased, and by using cream of lower fat per- 
centage the proportion of proteids can be increased. 

Much less can be said in favor of the other artificial prepa- 
rations of milk, such as the proprietary foods. Some of these 
are designed to be used with fresh cow's milk, and furnish a 
convenient means of beginning the administration of starch 
towards the end of the first year. In making a selection, prefer- 
ence should be given to those preparations in which the starch 
has been completely dextrinized. 

Another class of proprietary foods are widely advertised as 
perfect substitutes for mother's milk when simply diluted with 
water. Many of them contain a large amount of starch in an 
insoluble form, while the casein and fat in dried form differ 
widely from the same ingredients in cow's milk. This class of 
foods should never be employed to the exclusion of cow's milk, 
except as a temporary expedient. 



CHAPTER XIV. 

PRACTICAL RULES FOR FEEDING. 

One of the practical objections to the home modification of 
milk for infant feeding has been the length of time necessary 
to fully explain the process to the mother or nurse, time which 
few busy practitioners have to spare. The best way to obviate 
this difficulty is to have a printed list of directions to present 
to the mother. We have attempted to prepare such a list, 
which may be used or modified as the physician may desire. 
When the principles of cleanliness are once understood, the 
mother can easily apply them to any method of feeding, such 
as whey-cream mixtures, top-milk mixtures, etc. 

I. The milk should be obtained in bottles which have been 
filled and sealed at the dairy. 

II. As soon as the bottle is received it should be placed on 
ice until the day's food is to be prepared. 

III. All utensils which are to be employed in the milk- 
modification should be cleansed with boiling water, if possible, 
just before being used. 

IV. The following articles are necessary: (a) A jar of 
boiled water or freshly prepared barley-water. (b) A jar 
containing milk-sugar or granulated sugar, (c) A bowl con- 
taining freshly boiled water, in which stand a tablespoon, a 
knife, and a one-ounce dipper (for top-milk mixtures), (d) 
A freshly scalded eight-ounce glass graduate, (e) Two freshly 
scalded quart preserving jars and caps. (/) A bottle of lime- 
water, (g) An enamelled or glass funnel, freshly scalded. 

V. When the mixture is to be prepared, the mother or 
nurse should thoroughly wash her hands before placing these 
articles upon a clean napkin. The neck and cap of the bottle 

318 



PRACTICAL RULES FOR FEEDING. 319 

of milk (or cream) are next thoroughly cleansed with hot 
water. The pasteboard cap is then removed by inserting the 
knife under the edge. The upper half-inch of milk or cream 
may be removed with a spoon and discarded if the cap has been 
carelessly adjusted. 

VI. Eemove the upper ounces of top milk from the 

jar of milk with the dipper (gently pouring the first half- 
dipperful to allow space for the dipper to be inserted), or 

measure ounces of cream and ounces of whole milk 

(or skimmed milk) in the glass graduate. The milk and 
cream (or top milk), as they are measured, should be poured 
into one of the freshly scalded quart jars (No. I.). 

VII. Dissolve ounces of milk-sugar (or granulated 

sugar) in ounces of boiling water (in the graduate). 

Pour this at once into jar No. II. and add ounces of 

boiled water (or barley-water) ; ounces of lime-water 

(if desired) are then added. The contents of jar No. I. are 
then poured into jar No. II. and thoroughly mixed. It is 
then tightly capped and placed on ice until ready for use. 

N.B. — It is important to remember that any fluid used in the 
milk mixtures other than milk and cream is a diluent. The 
simplest method is to dilute milk and cream with water. 
Whatever diluents are added to our mixture, such as whey, 
barley-water, sugar solution, lime-water, etc., the total quan- 
tity of such diluents must be made to equal the total amount of 
diluent required. The sugar solution may be made with either 
plain water or barley-water. Holt recommends that the sugar 
of milk should be dissolved in boiling water. The amount of 
the latter should then be subtracted from the total amount of 
the solution. 

VIII. When the infant is to be fed the jar is again agitated 
and the proper quantity poured into a freshly scalded feeding- 
bottle through a freshly scalded funnel; the nipple, also 



320 THE ARTIFICIAL FEEDING OF INFANTS. 

freshly scalded, is then put on and the bottle stood in hot 
water until the milk feels warm to the back of the hand. Ex- 
ceptionally, or in summer, the child prefers it cool. In cases of 
extreme gastric irritability it may be better tolerated ice- 
cold. 

IX. Feeding-bottles should be cleansed with cold water as 
soon as the child has finished its meal, and kept filled with 
water until ready to be scalded for use. The bottles should 
have rounded corners so that they may be easy to clean. 

X. The rubber nipples should be thoroughly cleansed on 
both surfaces with soap and cold water and kept in a cup of 
borax solution until ready to be scalded for use. 

XL The baby should be fed : 

During the first month every hours from 

a.m. to p.m., with night feedings. ounces 

should be given at each feeding. 

During the second and third months give ounces every 

hours from a.m. to p.m., with night feed- 
ings. 

During the fourth and fifth months give ounces every 

hours from a.m. to p.m., with night feed- 
ings. 

From the sixth to the eighth month give ounces every 

hours from a.m. to p.m. No night feedings. 

From the ninth to the twelfth month give ounces every 

hours from a.m. to p.m. 

XII. The infant should be held in a reclining position to 
be fed, and should consume the whole amount in from fifteen 
to twenty minutes. Where there is difficulty in breathing, the 
time for the meal may be lengthened. Should the infant re- 
fuse the bottle before the entire quantity is consumed, after 
a short interval offer the bottle again. If it is again refused, 
the remainder of the milk should be thrown away and the 
infant should not be fed again until the proper interval has 
elapsed. 



PRACTICAL RULES FOR FEEDING. 321 

The practice of some mothers and nurses of moistening the 
nipple beforehand or putting it in the mouth to test the tem- 
perature of the milk cannot be too strongly condemned. 

Whenever possible, it is preferable to have separate feeding- 
bottles. After the total quantity for the day has been mixed 
and well shaken the bottles are to be filled through the scalded 
funnel and stoppered with sterile non-absorbent cotton. These 
cotton plugs should be made of sufficient size to tightly stop- 
per the feeding-bottles. The plugs may be sterilized by 
steaming them for three hours in a double boiler (such as is 
used in most households for cooking cereals). It is more con- 
venient to prepare a large quantity of these plugs at a time and 
to keep them in a scalded fruit jar, tightly capped. They will 
then remain approximately sterile. The stoppered feeding- 
bottles must be kept on ice and warmed when needed, the plug 
being then exchanged for a freshly scalded nipple. 

If top milk is to be used, the physician should ascertain 
when the milk was bottled, so that the necessary time for the 
raising of the cream may be allowed. The milkman should 
be requested to avoid any agitation of the bottles which would 
interfere with the raising of the cream. During warm weather 
the milk should be delivered only after some one is about 
to receive it and place it at once on ice. An hour's stand- 
ing on the doorstep in summer may render the milk unfit for 
use. 

The table which follows is intended to indicate the average 
amounts of the milk mixture to be given at each feeding and 
the intervals between meals. Since these are influenced by a 
variety of factors, such as the condition of the digestion, the 
gain in length and weight, etc., the table must be considered 
to represent only a normal average. It is rarely advisable to 
furnish the mother or nurse a list of directions covering ex- 
tensive periods of time, since they are only too apt to rely on 
them and to ignore evidences of indigestion, failure to gain in 
weight, etc., which require the physician's personal attention. 

21 



322 



THE ARTIFICIAL FEEDING OF INFANTS. 



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PRACTICAL RULES FOR FEEDING. 323 

It is always best to adhere as closely as possible to a given 
routine in regulating the intervals between meals. This ap- 
plies to the healthy as well as to the sick infant. There is less 
danger of the interval being too long than too short; if the 
child is sleeping at the time for his feeding, it is best not to 
disturb him. The succeeding meals should be given at the 
proper intervals, even if not on schedule time. 

It may be found that the infant will habitually oversleep; 
if he is healthy and gaining weight the longer interval may 
safely be allowed. Occasionally the infant will turn night into 
day by persistently oversleeping during the daytime and will 
want his food frequently at night. It is then necessary to 
waken him at proper intervals during the day and thus break 
up the habit. 

If an infant is born underweight and shows early evidences 
of indigestion, it may be necessary to adhere to the two-hour 
intervals and to weaker dilutions for several months. These 
cases cannot be considered normal, since the capacity of the 
stomach and the nutritional demands of the organism are 
usually less than those of the average child. They must be 
studied with especial care, and no absolute rules can be laid 
down for their management. 

Much oftener we encounter the difficulty of a too frequent 
desire for food. The conditions which render it advisable to 
increase the strength or the quantity of our milk mixture are: 
when the infant habitually cries after finishing his meal and 
continues to cry until the next feeding, when there are no 
signs of indigestion, and when it is impossible to find any other 
cause for his fretfulness. The change in the diet is particu- 
larly indicated when there is failure to gain in weight or the 
gain is persistently below normal. Habitual crying, however, 
is usually a sign of colic and indigestion and requires read- 
justment of the diet. Nearly all these cases show evidences 
of malnutrition, and their cry not only denotes pain, but also 
craving for a food which will satisfy the needs of their system. 



324 THE ARTIFICIAL FEEDING OF INFANTS. 

The principal difficulty in the management of these cases is 
the enforcement of sufficiently long intervals between meals. 
This should rarely be less than two hours; often a longer 
interval may be observed with advantage. A drink of plain 
water or of barley-water between meals will do no harm and 
will often suffice to quiet the child. When we are forced to 
feed the child on a milk mixture containing very low propor- 
tions of proteids and fat, which are insufficient for proper 
nutrition and growth, it is often desirable to supplement the 
diet with one of the predigested foods, such as liquid pepto- 
noids, panopepton, or predigested beef. Somatose and plasmon 
may also be used, but are not always well tolerated. These 
preparations can be given either with the meal or during the 
interval. 

In an entirely distinct class are those infants who are 
particularly robust from birth, and whose weight, length, 
arid rapidity of growth are above the normal. The food re- 
quirements of these cases may be from a month to six 
weeks in advance of the normal requirements of the average 
infant. 

If the infant vomits a few minutes after finishing his meal, 
before curdling has occurred, either too much milk has been 
taken or it has been consumed too quickly. To obviate this 
difficulty unpierced nipples should be procured in which the 
aperture can be made as small as desired, or the device of Bon- 
will 14 may be resorted to. He inverts a small nipple into the 
neck of the bottle; a short nipple is then put on in the usual 
manner. The advantages of this method are the vigorous suck- 
ing that it demands and the length of time required for the 
meal. It is obviously unsuited for weak infants. When re- 
gurgitation persists in spite of these measures, it is usually 
safer to reduce the quantity of the food mixture, since the 
amount is probably in excess of the gastric capacity; or the 
proportion of fat or proteids may be too high (Holt) and 
need reduction. The propriety of pasteurization or of sterili- 



PRACTICAL RULES FOR FEEDING. 325 

zation has already been discussed (page 293). If one or the 
other is considered desirable, it should be done as soon as the 
milk is received, and the milk should then be kept on ice until 
the day's mixing is to be done. If separate feeding-bottles 
are to be used, the process may be repeated when they are 
filled. 

During the heated term, when gastro-intestinal disorders 
are particularly apt to occur, great care should be exercised 
to avoid overtaxing the infant's digestion. If the child is 
taking a milk mixture of high proportions, containing from 
two to two and a half per cent, proteids and three and a half 
to four per cent, fat, it is usually a good plan to reduce the 
amount of fat in our mixture and to avoid increasing the pro- 
teids. With the first signs of gastro-intestinal disturbance, 
the proportion of both ingredients should be further decidedly 
reduced. 

The necessity for the administration of water to the infant 
is a point to which attention has repeatedly been called, but 
its importance is apt to be overlooked both by the mother 
and the physician. Water should be administered between 
feedings, preferably about half an hour before a meal; it 
should rarely be iced except during the summer months. The 
quantity to be given will depend on the infant's individual 
taste. 

Holt. 183 When a child has been well started on some 
method of feeding and has begun to gain regularly in weight, 
a regular weekly report in writing may often take the place of 
the physician's visit. This should include only answers to 
certain questions, — namely: 1. Weight: gain or loss since 
last report? 2. Stools: frequency and general character. 
3. Vomiting or regurgitation: when and how much? 4. 
Flatulence or colic ? 5. Appetite: is the child satisfied ? Does 
he leave any of his food? 6. Is he comfortable and good- 
natured? 7. How much does he sleep? 8. Date. 9. Date of 
last report. 



326 THE ARTIFICIAL FEEDING OF INFANTS. 

Method for calculating Milk Percentage without Formula?. 

For those who experience difficulty in estimating the strength 
of a mixture of cream, milk, whey, sugar solution, etc., in 
proteids, fat, sugar, and salts, the following table has been 
devised. The method of calculation is simple and fairly accu- 
rate. The first column represents the number of parts or 
ounces in the total daily quantity of the mixture. The per- 
centage strength of the different ingredients used must be 
multiplied by the number of parts used and then divided by 
the total number of parts, in order to ascertain the percentage 
strength of our whole mixture. An example is given of a 
milk, twelve per cent, cream, and seven per cent, sugar solution 
mixture. 



Parts. Proteids. Fats. Sugar. Salts. 

Milk 2 2X4 =8 2X4=8 2X4.5=9 2X0.7 =1.4 

Cream or top milk... 4 4X3.6 = 14.4 4X12 = 48 4X4.2 = 16.8 4X0.64 = 2.56 

Whey 

Sugar solution 10 10X7 = 70 

Diluent. — Barley- or 

plain water 

Lime-water 



Total 16) 22.4 56 95.8 3.96 

Percentage of our 
mixture equals 1.4 3.5 6.0 0.24 



Note. — It has been assumed that the percentage of proteids in whole 
milk is four; actually it will more frequently approximate 3.50. The 
higher figure is much more convenient for calculation, however, and can 
lead to no appreciable error if we recall that the actual amount of proteids 
present is from 0.1 to 0.3 lower than the figures indicate, according to the 
dilution employed. 



CHAP TEE XV 



ARTIFICIAL FOODS. 



According to Cautley. 38 proprietary foods may be classed 
as follows : 

Group I. Foods prepared from cow's milk. 

(a) Condensed milk without added sugar. 

( b ) Condensed milk with added sugar. 

(c) Peptonized milk. 

Group II. Foods prepared from cow's milk and modified cereals ; 
the starch unchanged or partially converted into dex- 
trin, etc. 

(ft) Containing much unchanged starch, — e.g., Nes- 
tle's. Anglo-Swiss, etc. 

(b) The starch largely converted into soluble carbo- 

hydrates, such as maltose and dextrin, — e.g.. 
Allen and Hanbury's. 

(c) Milk foods in which the milk has been partially 

peptonized or contains ferments which act on 
the addition of warm milk, and containing 
partially or entirely converted or unconverted 
starch, — e.g.. Benger's (prepared with milk), 
Carnrick's. Horlick's Malted Milk. 

Group III. Foods prepared from modified cereals only. 

(ft) The starch unchanged, — e.g., Robinson's Pre- 
pared Barley, Frame's Food. Ridge's Food, 
Xeave's Food. 

(6) The starch partially changed by the action of 
malt diastase. — e.g., Savory and Moore's 
Food. 

(c) The starch completely changed. — e.g., Mellims 
Food, Horlick's Food. 

327 



328 



THE ARTIFICIAL FEEDING OF INFANTS. 



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ARTIFICIAL FOODS. 329 

The table on page 328 is based on Leeds's analyses. These 
figures are subject to marked variation, as may be seen by 
reference to the results of other investigators. It may defi- 
nitely be accepted that the proportion of their ingredients is 
not a constant one. 

Monti " says that Nestle's, Ridge's, Mellin's Food, etc., con- 
tain too little fat and proteids. They are in no sense a fit sub- 
stitute for mother's milk, but may be used temporarily with 
good results. In the first months of life they should not form 
the exclusive nourishment. When the child is five months old 
and after weaning they are useful adjuvants. Theinhardt's 
Soluble Infant Food is similar to Mellin's Food. 

Cautley 38 states as an axiom that proprietary foods are 
unnecessary for the proper feeding of infants so long as good 
cow's milk, cream, and sugar are available. They should never 
be used before the sixth month, and then only as diluents. 

Starr 133 considers that proprietary foods are useful as 
mechanical attenuants, but unless they are prepared with milk 
it is questionable whether any of them can permanently meet 
the demands of nutrition. 

Rotch 119 calls particular attention to the unreliability and 
lack of uniformity in the composition of artificial foods, which 
" vary too greatly in their analyses to keep even within the 
acknowledged varying limits of human milk." 

J. Lewis Smith 129 considers them useful only as adjuvants. 

Biedert 7 recommends the prepared foods, added to the 
milk mixture, after the sixth month as a good method of begin- 
ning the administration of starch. Bendix says that their only 
proper use is in addition to other foods, for short periods of 
time, and never before three months. Scurvy may undoubtedly 
follow their prolonged use. 

Bagixsky. 5 The infant foods may be used after the third 
month as an adjuvant to mother's milk ; but the experience of 
all authors shows that the long-continued use of any of them 
causes a slight dyspepsia. Demme has observed a diminution 



330 THE ARTIFICIAL FEEDING OF INFANTS. 

in the number of red corpuscles in children who are fed too 
early on starch. 

Ashby and Wright 2 consider the artificial foods only useful 
temporarily, during a journey, etc., or when milk will not agree 
in any form. They do not readily ferment, but if used for 
too long a time, especially if the children are more than six 
months old, both rickets and scurvy are apt to ensue. 

Drews and Krauss 85 have found that somatose is well 
digested by healthy as well as poorly developed infants. It 
produced a finer curd when mixed with cow's milk. Krauss 
found it odorless and its taste not objectionable. Small doses 
seemed to increase peristalsis without exciting the secretions 
of the intestines. It was useful in all disturbances of diges- 
tion in infants, and was especially valuable in replacing the 
nitrogenous loss in the organism. Wolf 156 also reports good 
results with somatose in the feeding of infants; it was well 
borne in gastro-intestinal disorders and by atrophic infants. 

Condensed Milk. 

Monti." There are two principal varieties of condensed 
milk, one with and the other without sugar. To prepare the 
first, cow's milk with more or less sugar added to it is con- 
densed in a vacuum. It then contains all the constituents in 
an unaltered form if the process is correctly carried out. Fre- 
quently, on opening the cans, we find the contents covered 
with a skim composed of crystallized sugar and dried milk 
materials, under which the milk will keep for a long time, 
Microscopically, we find fat-droplets intact and numerous sugar 
crystals. Fermentation fungi are present only when the can 
has been open for some time. The high sugar content is apt to 
be a source of digestive disturbances and a frequent cause of 
the failure of condensed milk as a food. It may cause rickets, 
furunculosis, anaemia, etc. Therefore it is only to be used 
temporarily during journeys, in the summer months, etc. 

The second variety of condensed milk is prepared by heating 



ARTIFICIAL FOODS. 331 

milk for a short time above 100° C. and then evaporating in a 
vacuum at about 60° C. to a third of its former volume. 
Monti has had no good results from its use. 

Cautley. 38 On account of the excess of sugar present in 
condensed milk, children fed on it become fat, flabby, and 
anaemic. Not enough proteids are present properly to nourish 
the tissues. If no other food is given, rickets, scurvy, bron- 
chitis, and gastro-enteritis may develop. It is useful only as 
a temporary food when good cow ? s milk cannot be obtained 
or to tide over an emergency. It is apt to spoil after opening, 
it is not always sterile, and the composition of different brands 
is apt to vary. 

Ashby and Wright 2 recommend its use for short periods 
of time, as it is sterile and does not curdle easily. Too pro- 
longed use is apt to produce scurvy. It should be diluted in 
the proportion of one to eight or one to ten. Only those brands 
should be selected which contain plenty of fat. Some contain 
almost twelve per cent. Clinical experience teaches that it is 
sometimes retained when so-called fresh milk is vomited or 
gives rise to flatulence or colic. 

Starr 133 considers it valuable as a temporary change of diet 
when travelling, or when cow's milk cannot be obtained. It 
contains too much cane-sugar and not enough nutrient material 
for the needs of a growing baby. Infants fed on it, though 
fat, are pale, lethargic, and flabby ; they possess little resistance 
to disease; dentition is often delayed and rickets is likely to 
result. If the milk is kept too long, or the packing has been 
imperfect, it is liable to undergo decomposition. 

Fenwick 52 makes the same criticisms as the above and calls 
attention to the wide variations in the percentage of fat in 
different brands, some containing scarcely any. He, too, 
advises that it should be used only temporarily. 

E. W. Saunders 125 points out some of the advantages of con- 
densed milk which probably explain its popularity. 

I. Bad milk cannot be condensed, and the large proportion 



332 THE ARTIFICIAL FEEDING OF INFANTS. 

of sugar serves to keep it, although the bacteria are not de- 
stroyed thereby. 

II. Practically, it is found that condensation produces 
molecular changes in casein, which are very advantageous. 
The curd produced by the action of rennet or acids is inter- 
mediate in size between that of mother's milk and cow's milk. 

III. The fat-globules are kept in perfect emulsion, so that it 
is impossible to separate them in the centrifuge. Of course, 
the fat is greatly deficient in amount ; however, this small 
amount of fat is more available than that of fresh milk because 
of its perfect emulsion and from the fact that the curd of con- 
densed milk, in the meshes of which some of the fat is en- 
tangled, is more digestible than that of fresh milk. Saunders 
believes that condensed milk should never be used for any 
length of time without being fortified by cream or cod-liver oil. 
In addition, he makes a plea for dairy hygiene, the immediate 
cooling of fresh milk, and the maintenance of a low tempera- 
ture until it is used. 

George Carpenter 36 declares that Swiss cows are more 
subject to tuberculosis than other breeds, the average being 
about eighty-five per cent. Swiss condensed milk is prepared 
by evaporating in vacuo, so that it is not sterilized. The com- 
pleted product is therefore liable to contain tubercle bacilli in 
an active state. 

Peptonized Milk. 

Cautley 38 considers peptonized milk valuable for tempo- 
rary use because of its ease of digestion. It should not be 
continued for a long period, since it does not furnish the 
physiological stimulus to the natural secretions. The pep- 
tones and albumoses which it contains may cause diarrhoea. 
A certain amount of intelligence is necessary for its proper 
preparation. 

Ashby and Wright. 2 Clinical experience has proved its 
undoubted value. Partially peptonized milk curdles less 
readily than raw milk and the curd is softer. It must not be 



ARTIFICIAL FOODS. 333 

given for too long a period as the sole food, lest scurvy develop. 
Generally speaking, it is more useful in gastric than in intes- 
tinal affections. 

Botch. 119 " Peptonized milk, as a food for the young infant, 
consists of too large an amount of digested proteids, too little 
sugar, and a very large over-proportion of mineral matters." 
It may be of use to tide over a period of difficulty until the 
infant's stomach has recovered its digestive power, but the in- 
dications for its employment may be met by a proper regula- 
tion of the proteids in the child's food in a more rational man- 
ner. The infant's stomach is intended to digest proteids and 
not to have the proteids digested for it. 

Starr. 133 When properly prepared, peptonized milk presents 
great advantages in that the necessity to use lime-water, barley- 
water, and other starchy attenuants is done away with. The 
return to the ordinary milk diet can be made gradually by 
diminishing the time of the artificial digestion of the milk 
until pure milk can be again used. It presents the albuminoids 
in a minutely coagulable and digestible form. It has an alka- 
line reaction, contains the proper proportion of lactose, salts, 
and fat, and if only partially peptonized is not bitter to the 
taste. 

Fenwick 52 thinks that its prolonged use results in enfeeble - 
ment of the digestive organs of the infant, and may lead to 
anaemia, rickets, and symptoms allied to scurvy. 



APPENDIX. 

¥¥ 

A. Bichmond. The composition of Peptonized Milk (un- 
diluted) is given as follows by Vieth : 



Per cent. 

Water 89.20 

Fat 3.41 

Sugar 3.80 

Casein 0.96 



Per cent. 

Albumin 0.07 

Albumoses 1.88 

Ash 0.68 



Composition of Eagle Brand Condensed Milk (Holt) : 



Undiluted. 

Per cent. 

Fat 6.94 

Proteids 8.43 

Sugar 50.69 

Salts 1.39 

Water 31.30 



Diluted with six 

parts of water. 

Per cent. 


Diluted with twelve 

parts of water. 

Per cent. 


0.99 


0.53 


1.20 


0.65 


7.23 


3.90 


0.17 


0.10 


90.49 


94.82 



Composition of Swiss, Austrian, and Norwegian Con- 
densed Milk (Holt) : 



Water and volatile substances. 

Salts 

Fats 

Albuminoids 

Lactose , 

Cane-sugar 



Vith sugar. 


Without sugar 


Per cent. 


Per cent. 


20.0-30 


46.5-55 


1.5-3 


2.0-3 


8.0-12 


13.0-20 


10.0-13 


13.5-27 


10.0-15 


12.5-18 


30.0-45 





335 



16 APPENDIX. 

Composition of Whet from forty-six analyses by Konig: 

Percent. 

Fat - 0.32 

Proteids 0.86 

Sugar 4. 79 

Salts 0165 

Water -: :; 

Monti's estimate ifi : 

?,r :--: 

Fat 1.00 

f Casein '! 

~ | Soluble albumin 0.80-1.00 

Sogau 1.50- 

Salts 0.70 

^V:.1r- 



Composition of Beep Juice HoL: 



Fai 

Proteids . . . 

Extractives , 
Water 

Salts 



Expressed by the warm process. 

one pound grves two and 

a half ounces. 

Percent. 

0.6fl 

2.90 

3.40 

92.90 

- at 



ZZ - Z- :~ ''--. :■'.'-- :r: res- :f 
z Z-z':. ~^r'z i'-zz: :"- It- 

:-. - - - : r . ' 

a third oar. : - - 

7:1 It" 



3.00 
1.90 

n 20 



Composition of Beep Beoth i Holt) : 



PniffeidB.. . . 

Extractives . 



FtH .zz: 

1.02 

1.8a 



Salts.. 

TV;.:- 



7r: it-: 



APPENDIX. 337 

Composition of Barley- Water (Holt) : 

Per cent. Per cent. 

Proteids 0.09 Starch 1.63 

Fat 0.05 Water 98.20 

Salts 0.03 

Barley- Water is made as follows. Add two teaspoonfuls 
of washed pearl barley to a pint of water; boil slowly down to 
two-thirds of a pint and strain. 

Oatateal or Cracked Wheat Water (Starr). 
Add one tablespoonful of well-cooked oatmeal or cracked 
wheat to a pint of water ; allow it to simmer slowly for an hour 
or two, stirring constantly until a smooth mixture is obtained. 
Strain. 

Bice-Water. 
Soak one ounce of well-washed rice in a quart of water for 
two or three hours at a moderate heat; then boil for an hour 
and strain. 

Barley Jelly (Starr). 
Put two tablespoonfuls of barley flour into a quart saucepan 
with one and a half pints of water ; boil slowly down to a pint. 
Strain and allow the liquid to set into a jelly. 

Eaw Beef Juice (Warm Process) (Starr). 
Take one pound of sirloin beef, warm it on a broiler before 
a quick fire, and cut into small cubes. Express the juice with 
a meat press or a lemon squeezer. Eemove the fat that rises on 
cooling. Do not actually coolc the meat. Flavor with salt. 
Warm before giving, but do not heat sufficiently to coagulate 
the albumin. 

22 



338 APPENDIX. 

Eaw Beef Juice (Cold Process) (Holt). 
Take one pound of finely chopped lean beef and eight ounces 
of water, allow to stand in a covered jar upon ice from six to 
twelve hours; then squeeze out the juice by twisting the meat 
in coarse muslin. Season with salt. 



Beef Broth (Starr). 
Mince one pound of lean beef, put it with its juice into an 
earthen vessel containing a pint of water at 85° F., and let it 
stand for one hour. Strain through stout muslin, squeezing 
all the juice from the meat. Place this liquid on the fire and, 
while stirring briskly, heat slowly just to the boiling point; 
then remove at once and season with salt. 

Mutton Broth (Starr). 
Add one pound of loin of mutton to three pints of water. 
Boil gently until very tender, adding a little salt; strain into 
a basin, and when cold skim off the fat. Warm when serving. 

Chicken Broth (Starr). 
A small chicken or half of a large fowl, thoroughly cleaned 
and with all the skin and fat removed, is to be chopped, bones 
and all, into small pieces. Put them with salt into a small 
saucepan and add a quart of boiling water; cover closely and 
simmer over a slow fire for two hours. After removing, allow 
it to stand, still covered, for an hour; then strain through a 
sieve. 

Veal Broth (Starr). 
Mince from one-half to one pound of lean veal and pour 
upon it a pint of cold water. Let it stand for three hours, 
then slowly heat to the boiling point. After boiling briskly for 
two minutes, strain through a fine sieve and season with salt. 



APPENDIX. 339 

Egg-Water. 

Add the white of one egg and a pinch of salt to six ounces 
of cold water and mix thoroughly. This will be more palatable 
if sweetened. 

Dextrintzed Gruel (Chapin). 

To one pint of gruel (made by boiling for fifteen minutes 
one tablespoonful of wheat, oatmeal, or barley flour with one 
and a half pints of water) add, when cool enough to be tasted, 
one teaspoonful of diastase or " Cereo" or of a thick malt 
extract. This mixture should be kept at a temperature of 
150° F. for from fifteen to twenty minutes, until the gruel 
becomes thin and watery. The conversion of starch into dextrin 
and maltose will then be complete. 

Peptonized Milk. 

1. Eapid method. Take half a pint of milk, half a pint of 
water, two ounces of cream, and one measure of peptogenic 
milk-powder. Place on the range and bring to a boil in ten 
minutes. This should be cooled and kept in the refrigerator 
until used. 

2. Use the same quantities as above and place the mixture 
on the back of the range or in water of a temperature of 115° 
F. for thirty minutes; then remove and put on ice or else bring 
the mixture quickly to the boiling point to destroy the activity 
of the digestive ferments. 

3. If the same process as ~No. 2 is carried out for two hours 
the conversion of the casein into albumoses and peptones will 
be complete. (One measure or capful of peptogenic milk- 
powder must be added for each pint of the mixture prepared.) 

Peptogenic milk-powder consists of sodium bicarbonate, pan- 
creatin, and milk-sugar. 

Liebig's Food (Leeds). 
Take equal parts of wheat flour and barley malt, to which 
a certain amount of wheat bran is added (on account of the 



340 APPENDIX. 

phosphates and nitrogenous matter it contains). One per cent, 
of potassium bicarbonate is also added, and the whole is stirred 
with enough water to make a thin paste. It is then allowed 
to stand for several hours and heated to 150° F. until the 
conversion of the starch into maltose and dextrin is completed. 
The strained residue is then pressed and exhausted with warm 
water. The extract is evaporated and dried into a powdery 
mass. 

Liebig's Soup (Monti). 

Twenty cubic centimetres of wheat flour are mixed cold 
with two hundred cubic centimetres of unskimmed milk. The 
meal must be thoroughly mixed and heated over a slow fire 
(Mixture No. 1). 

Twenty cubic centimetres of malted barley are mixed with 
forty cubic centimetres of a one per cent, solution of potassium 
carbonate. This is left standing for half an hour and then mixed 
with No. 1. After stirring for fifteen minutes it is heated to 
boiling and then strained. On account of the starch, it cannot 
be used before the fifth month. Children fed on it are subject 
to rickets, etc. It can, however, be added to the nourishment 
in the case of older infants when the supply of mother's milk 
is insufficient. It can also be used in weaning. 

Scraped Meat. 
Take a piece of raw juicy steak and scrape away the pulp of 
the meat with a dull knife or a piece of glass. Place this meat 
pulp (as much as is needed) on a piece of toast or stale bread 
and bake in the oven for five minutes. Flavor with salt and a 
small amount of butter. It can be administered either with 
or without the toast. 

Oat Jelly (Kotch). 
Two ounces of coarse oatmeal are soaked in a quart of cold 
water for twelve hours. The mixture is then boiled down so 



APPENDIX. 341 

as to make a pint and strained while hot. On cooling, a jelly 
is formed. Keep on ice until needed. 

B. Henry Leffmann. Methods of Milk Analysis. — For 
the determination of the proteids in milk two methods are 
in common use, termed respectively the Ritthausen and the 
Kjeldahl method. Each has been modified in details by differ- 
ent analysts. The Ritthausen method depends on the precipi- 
tation of the proteid matter by a copper salt and subsequent 
weighing of the curd so obtained, with due allowance for the 
fat and mineral matter that may be present. The Kjeldahl 
method depends on the conversion of the nitrogen into ammo- 
nium compounds and subsequent estimation of the ammonium. 
The amount of proteids is calculated by the use of the factor 
based upon the analysis of the different proteid matters. The 
Ritthausen method is subject to errors, most of which tend to 
increase the figures for the proteids. The Kjeldahl method is 
also subject to errors, some of which tend to diminish the 
figure for the proteids ; but the principal errors in this method 
are that any non-proteid nitrogen (that is, the so-called ex- 
tractives) is counted as proteid; secondly and more seriously, 
the factor for calculation is uncertain, as it differs with each 
form of proteid. American chemists usually employ 6.25 for 
cow's milk proteid; some prominent English chemists use 
6.33. A factor as high as 6.67 has been recommended. 

C. A Clinical Method for the Estimation of Breast-Milk 

Proteids. 
George Woodward. 149 Ten cubic centimetres of the milk 
to be tested are placed in two glass burettes (five cubic centi- 
metres in each) constructed with a glass pinchcock at the lower 
end to facilitate drawing off the serum. The burettes are then 
placed in a warm spot (from 95° to 100° F.) to favor fer- 
mentation. The time required to obtain distinct precipitation 
of the casein is from eighteen to twenty-four hours. When 



342 APPENDIX. 

the cream has fully separated as a solid yellow layer, the 
burettes are placed in cold water to increase the viscosity of 
the cream and from each the five cubic centimetres of serum 
are drawn into fifteen-cubic-centimetre graduated centrifu- 
gating tubes, leaving the cream in situ. The tubes are then 
filled to the fifteen-cubic-centimetre mark with Esbach solution 
(picric acid five grammes, citric acid ten grammes, water five 
hundred cubic centimetres). 

The mixture is stirred with a glass rod and then revolved 
in a hand centrifuge until a constant reading is obtained. 
The estimates from the two tubes are taken and a mean derived 
from the sum of these. By a Kjeldahl control Woodward 
found this method to be fairly exact. 

Leffmann-Beam Method for the Estimation of Fat. 

D. The Leffmann-Beam method 257 for the estimation of 
the fat in milk or cream requires a specially constructed cen- 
trifugal machine and test-bottles with a capacity of thirty cubic 
centimetres, provided with a graduated neck, each division of 
which represents one-tenth per cent, by weight of butter fat. 

" Fifteen cubic centimetres of the milk are measured into 
the bottle, three cubic centimetres of a mixture of equal parts 
of amyl alcohol and strong hydrochloric acid added, mixed, 
the bottle filled nearly to the neck with concentrated sulphuric 
acid, and the liquids mixed by holding the bottle by the neck 
and giving it a gyratory motion. The neck is now filled to 
about the zero point with a mixture of sulphuric acid and 
water prepared at the time. It is then placed in the centrifu- 
gal machine, which is so arranged that when at rest the bottles 
are in a vertical position. If only one test is to be made, the 
equilibrium of the machine is maintained by means of a test- 
bottle or bottles filled with a mixture of equal parts of sul- 
phuric acid and water. After rotation from one to two min- 
utes, the fat will collect in the neck of the bottle and the 
percentage may be read off. It is convenient to use a pair of 



APPENDIX. 343 

dividers in making the reading. The legs of these are placed 
at the npper and lower limits respectively of the fat, making 
allowance for the meniscus; one leg is then placed at the zero 
point and the reading made with the other. The results do 
not vary from those obtained by the Adams process by more 
than one-tenth per cent, and are generally even closer. 

" Cream is to be diluted to exactly ten times its volume, the 
specific gravity taken, and the liquid treated as a milk. Since 
in the graduation of the test-bottles a specific gravity of 1030 
is assumed, the reading must be increased in proportion. 

" A more accurate result may be obtained by weighing in 
the test-bottle about two cubic centimetres of the cream and 
diluting to about fifteen cubic centimetres. The reading ob- 
tained is to be multiplied by 15.45 and divided by the weight 
in grammes of cream taken." 

Modification of the Leffmann-Beam Method. 197 
A specially constructed graduated milk-bottle is required 
which will fit into any centrifuge used for urinalysis, etc. 
Five cubic centimetres of milk are introduced into the milk- 
bottle through a small pipette; one cubic centimetre of 
Eeagent No. 1 is added, and the bottle well shaken. (Eeagent 
No. 1 : fusel oil thirty-seven parts by volume, wood alcohol 
thirteen parts, hydrochloric acid fifty parts.) Eeagent No. 2 
(sulphuric acid of a specific gravity of 1832) is added little 
by little with constant agitation until the bottle is filled to the 
base of the graduated neck. A mixture of equal parts of sul- 
phuric acid and water is then added to reach a little above the 
highest (or first) graduation mark. The bottle is then whirled 
in the centrifuge for two minutes ; the fat will then have risen 
in a clear yellowish layer which can be read in percentages 
from the scale on the neck of the bottle. If the milk be richer 
than five per cent, of fat, dilute equally with water. In testing 
cream, mix five parts of cream with twenty parts of water. 
The result should be multiplied by five. 



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225. Pfaundler. Wiener Klinische Wochenschrift, No. 44, 1897. 

226. Bendix, Bernhard. Berliner Klinik, Bd. xiii., 1900. 

227. Schlesinger, Emil. Berliner Klinische Wochenschrift, No. 7, 

1901. 

228. Keller, Arthur. Centralblatt fur Innere Medizin, No. 2, 1900. 

229. Comby. Maladies de TEnfance, 2d edition, Paris. 

230. Johannessen, Axel. Jahrbuch fiir Kinderheilkunde, Bd. liii., 

1901. 

231. Holt, L. E. Abstract in Archives of Pediatrics, January, 1901. 

232. Knopfelmacher. Jahrbuch fiir Kinderheilkunde, October, 1900. 

233. Eachford, B. M. Archives of Pediatrics, vol. xvii., 1900. 

234. Conn, H. W. Abstract in Archives of Pediatrics, vol. xvii., 

1900. 

235. Winters, J. C. The Feeding of Infants, New York, 1901. 

236. Jemma. Abstract in Archives of Pediatrics, January, 1901. 

237. Biedert, Ph. Neue Untersuchungen und Klinische Beobach- 

tungen von Menschen und Kuhmilch als Kinderernahrung, 
Virchow's Archiv, Bd. lx., 1874. 

238. Carter, Alfred H. Birmingham Medical Record, vol. xlii., 1897. 

239. Crandall, Floyd M. Medical News, vol. lxxviii. 

240. Conradi. Miinchener Medizinische Wochenschrift, January 29, 

1901. 

241. Schlossmann, Arthur. Archiv fiir Kinderheilkunde, Bd. xxx., 

1900. 

242. Bell, J. Finley. Medical News, No. 77, 1900. 

243. Camerer, Wilhelm. Der Stoffwechsel des Kindes, 7th edition, 

Tubingen, 1896. 

244. Edlefsen. Miinchener Medizinische Wochenschrift, January 1, 

1901. 

23 



354 BIBLIOGRAPHY. 

245. Stokes, William E., and Wegefarth, G. Medical News, vol. 

lxxi., 1897. 

246. Estes. Annales de Medecine et de Chirurgie Infantile, 1900. 

247. Chapin, H. D. Medical Eecord, July 6, 1901. 

248. Chapin, H. D. New York Medical Journal, February 23, 1901. 

249. Woodward, George. Journal of Experimental Medicine, March, 

1897. 

250. Hamilton, Edward. American Journal of Obstetrics, October, 

1901. 

251. Starr, Louis. Diet Lists. 

252. Fischer, Louis. Infant Feeding, 2d edition, Philadelphia, 1901. 

253. Botch, T. M. Pediatrics, 3d edition, Philadelphia, J. B. Lippin- 

cott Co., 1901. 

254. Westcott, T. S. American Journal of the Medical Sciences, 

October, 1901. 

255. Eussell, H. L. Philadelphia Medical Journal, October 16, 1901. 

256. Starr, Louis. Diseases of the Digestive Organs in Infancy and 

Childhood, 3d edition, Philadelphia, 1901. 

257. Leffmann and Beam. Analysis of Milk and Milk Products, 

Philadelphia, 1895. 

258. Bulletin No. 75. Department of Agriculture, Pennsylvania, 

1901. 

259. Bang, Professor. Address at the British Congress on Tubercu- 

losis, 1901. 

260. Ravenel, M. P. Journal of Comparative Medicine and Veteri- 

nary Archives, April, 1898. 

261. Koch, Eobert. Address at the British Congress on Tuberculosis, 

Lancet, July 23, 1901. 



INDEX, 



Absorption, gastric, 69, 70, 73, 92 

intestinal, 82, 83, 92 
Acid, acetic, 73, 87, 88 

butyric, 73, 87, 88 

hydrochloric, 68, 70-77, 197 

lactic, 55, 69-75, 77, 82, 87, 88 

valeric, 87, 88 
Acidity, best means to overcome, 130, 162, 166 
Acids, fatty, 82, 88 
Adriance, 19, 21, 25, 31, 271 
Alcohol, 176 

Alkaloids in cow's milk, 215 
Amido-acids, 82, 83 
Anabolic ratio, 258 
Annotto, 180 
Armstrong, John, 9 
Arrowroot- water, 13, 118 
Artificial digestion, experiments in, 84, 85 
raw and sterilized milk, 234, 235 
Ass's milk, 9, 10, 44 

B 

Backhaus, 198 

Milk, 99, 103, 108 
Bacteria, action of, on starch, 214 
on sugar, 214 
as agents of fermentation, 212 

of putrefaction, 213 
in cow's milk, 181, 182, 191 
anaerobic, 205, 206 
color-producing, 208 
lactic acid, 201, 202 
lactic vs. peptonizing, 207 
peptonizing, 204-207 

355 



356 INDEX. 

Bacteria in cow's milk, peptonizing spores, 204, 205. 
saprophytic, 200 
thermal death-point of, 219, 220 
thermophile, 206 

in faeces, 197 

in intestinal digestion, 81, 83, 211-213 

in meconium, 197 

in mother's milk, 199 

in stomach, 197 

rapidity of growth of, 198 
Baner, William L., 300 
Bang, 219 
Barley jelly, 337 

water, composition and preparation of, 337 
Bauer and Deutsch, 72-74 
Beef juice, 172, 175, 291, 292, 336-338. 
Beef peptonoids, 175, 291, 292 
Bendix, 99, 169 
Biedert, 25, 26, 94, 212 
Biedert's Cream Conserve, 95, 96, 105. 

Mixture, 95, 105, 267, 268 
Bile, 80, 81, 90 
Blackader, 220, 221 
Blauberg, 27, 88, 266 
Boiling milk, 231 

objections to, 232 
Boissard, 118 
Bonwill, 324 

Bottled milk, dangers of, 180 
Bread and butter, 173 
Broths, 9-11, 172, 175, 291, 292, 338 
Budin, 118 
Buttermilk, 113, 285 



Calories, 115, 258, 260, 261 

Calorimetric method of feeding, 96-99 

Carstens, 228 

Carter and Bichmond, 29 

Cattle, best breeds of, for dairy purposes, 186 

feeding of, 188 
Cautley, 163, 186, 188, 242, 250, 273, 327 



INDEX. 357 

Centrifugal cream, advantages of, 144, 150, 287, 288 

objections to, 107, 117, 158 
Centrifugation, effect of, on bacterial content, 60 

on fat emulsion, 149, 150, 157, 158 
Cereal coffee, 176 
Certified milk, 49, 185, 276 
Chapin, H. Dwight, 158, 310 
Chapin's dipper, 311 
Chicken in infant's diet, 175 
Cholesterin, 80, 81, 86, 90 
Chyme, 68 
Clarke, John, 10 

Coagulation of cow's milk, effect of acids on, 66 
of fat on, 68 

of heat on, 52, 85, 220, 221 
of starch on, 10, 159, 163 
of whey on, 106, 107 
Cocoa, 176 
Cod-liver oil, 59, 164 
Coffee as a stimulant, 176 
Cohn, 73 

Coit, Henry L., 184, 300 
Collins, H. Johnson, 209 
Comby, 118, 168 

Commercial cream, dangers of, 288, 298 
Condensed milk, 286, 315, 316, 330-332 

composition of, 335 
Conn, H. W., 202, 210 
Conradi, 221 

Constituents of average diet for infant six months old, 256 
Coriat, J. H., 84 
Cow's milk, albumose in, 51 
ash in, 56 

average composition of, 46-49 
casein, 50, 52, 53 

affinity of, for calcium salts, 52, 56 
ferments in, 204 
coagulation of, 56, 68 
forms of, 66, 67 

of, compared with mother's milk, 68, 282 
with acetic acid, 54 
colostrum in, 46, 47 



358 INDEX. 

Cow's milk, contamination of, 179-182, 200 

description of, 46 

English standard, 47 

fat in, 54, 55 

fermentation of sugar in, 55 

filtration of, 60 

gases in, 59 

impurities in, 201 

inspection of, 193 

iron in, 56 

lactalbumin in, 50, 52, 53 

lacto-globulin in, 51, 52 

lecithin in, 55, 57, 58 

nucleon in, 57, 58 

ordinary method of handling, 179 

phosphates in, 58 

phosphorus in, 53, 57-59 

produced by different breeds of cattle, 48 

proportions of albuminoids in, 52 

reaction, 44 

salts in, 56-58 

specific gravity of, 44, 45 

Storches' mucoid-proteid in, 51 

strippings, 50 

sugar in, 55 

sulphur in, 53 

total acidity of, 104 

variations in composition of, 46, 47, 49, 60 
Crandall, Floyd M., 160 
Cream mixtures, 10, 299, 300 

with condensed milk, 317 
necessity for, 14 

percentage composition of, 155, 299 
raising, effect of temperature on, 314 
thickener, 180, 181 
Cuthbert, Walter M., 312 
Czerny, 114 

D 

Dairy farm regulations, 183, 187, 188, 189-193 

in Denmark, 192 
Defecation, 85 



INDEX. 359 



Dextrinized gruels, 159, 160, 164, 339 
Diastase, decoctions of, 159 
Diet during second year of infancy, 174-178 
Digestion, 61 

gastric, 62, 65, 69, 70, 76, 77 

intestinal, 78, 81 

summary of, 84 
Digestive equilibrium, 154 

ferments, 61, 66, 68, 75, 80, 81 
Dilution, dangers of, 114 
Douglass, Carstairs, 223 
Drews, 330 
Duclaux, 205 

E 

Eberle, 197 

Edlefsen, 57 

Edsall, 60 

Egg albumin, 158, 160, 175, 291 

Egg-water, 339 

Egg-yolk, 160, 166, 172 

Enzymes, diastatic, 81, 82 

fat- splitting, 82 

intestinal, 84, 90, 214 

saccharifying, 82 

vegetable, 85 
Escherich, 212, 213 
Estes, 181 
Excretion, 85 

F 

Faeces, amount of, 87 
analyses of, 87-90 
bacteria in, 88, 90 
casein flakes in, 87, 91 
color of, 87, 88, 91 
examination of, 91, 92 
fat percentage of, 89 
ferments of, 90 

from a diet of cow's milk, 90, 91 
from a diet of mother's milk, 91 
mucus in, 90, 91 
nucleins in, 90, 91 



360 INDEX. 

Faeces, pigment of, 87 

reaction of, 87, 88, 91 

toxicity of, 88 

urobilin in, 87 
Fat, effect of ferments on, 82 

emulsion of, 83 

emulsions, effect of transportation on, 157 

in barley-water, whey, gravity and centrifugal cream mix- 
tures, 157 

proper proportion of, 285-287 

saponification of, 83 
Fat diarrhoea, 95, 121, 253 
Feeding of difficult cases, 137-139, 155, 156, 284, 285 

size of meals, 65, 97, 281 
Feeding-bottles, 12, 321 
Feer, 97 

Fenwick, W. Soltau, 61, 75, 164 
Filatow, 113 

Filtration through cotton, 235, 236 
Fischer, Louis, 161 
Fliigge, 205 
Frank, J. P., 9 
Freeman, R. G., 217, 218 
Freezing of milk, 233 
Fruit, 174 



Gaertner's Milk, 99, 103, 109, 110 
Gastric fermentation, 77 

juice, antiseptic action of, 212 

chemistry of, 70-77 

reaction of, 66 
Gerhardt, Carl, 13 
Gernsheim, 227, 228 
Getty, 222 

Gittings's dipper, 313 
Goat's milk, 44 
Gregor, 112 

Gregor's Malt Soup, 112 
Griffith, J. P. Crozer, 244 
Growth during infancy (see Weight and Growth) 



INDEX. 361 

H 



Hamilton, 303 

Harrington, 50 

Hayeru and Winter, 70 

Henoch, 100 

Heubner, 25, 96, 97 

Heubner's Mixture, 96, 97, 104, 151, 267 

Hoffmann's analyses, 27 

Holt, 128, 169, 174 

Holt's weekly report, 325 

Home modification, 131, 147, 148, 158, 296 

Huddleston, 194 

Hygiene in infant feeding, importance of, 99, 101, 140 



Importance of a pure milk supply, 196, 197, 216 

of fresh cream, 196 
Inadequate nursing, symptoms of, 135, 136 
Indigestion, symptoms of, 135, 136 
Individualization, necessity for, 96, 99-101, 277 
Indol, 83, 88 

Intervals between feedings, 281, 323 
Intestinal fermentation, 81, 213 

gases, 89 

putrefaction, 83, 84, 87 

reaction, 213 
Intestine, anatomy of, 78, 79, 85, 86 
Intoxications through milk, 214, 215 
Iron in metabolism, 253-255 



Jacobi, 119, 174 
Johannessen, 25, 40 



Kalischer, 207 

Keller, Arthur, 114, 253 

Klimmer, 187, 205 



K 



362 INDEX. 

Koch, Robert, 210 
Koeppe, 39 
Konig, 27 
Koplik, 151, 152 
Krauss, 330 



Laboratory milk, 128, 150, 158, 279, 280 

objections to, 126-128, 161 
Lactase, 55, 69, 81, 82 
Lactic acid fermentation, 69, 82, 212 
Lactic ferments in cow's milk, 201 
Lactose, 69, 82, 156, 164 
Lahmann's Vegetable Milk, 103, 108 
Langermann, 197 
Lecithin, 90, 256 
Leeds, 18, 30, 39, 160 
Leffmann, Henry, 341 
Leffmann-Beam method of fat analysis, 342 

modified, 343 
Lehmann, 27 
Liebig's food, 339 

soup, 340 
Lime salts in metabolism, 255, 289 
Lime-water, 292 
Lipase, 82 
Loefiund's Cream Conserve, 103, 109 

Peptonized Milk, 109 



M 

Malt extract, 176 

soup, 112, 265 
Maltose, 115, 264 
Marcel and Labbe, 70 
Mare's milk, 44 
Marfan, A. B., 116, 200, 259 
Marfan's Mixture, 105 
Mathematical formulae for modification: Coit, 300; Baner, 300, 301 

Hamilton, 303; Westcott, 301-303, 305-309 
Meconium, 80, 81, 86, 197 



INDEX. 363 

Meigs, Arthur V., 15, 25 
Meigs's, Arthur V., Mixture, 15, 16, 17, 153 
Meigs, J. Forsyth, 13 
Meigs's, J. Forsyth, Mixture, 13, 296 
Metabolic ratio, 258 
Metabolism, 58, 250 
experiments, 266 
mineral salts in, 266 
Method of calculating percentages without formulae, 306, 307, 326 
Methods of feeding: whole milk, 277; moderate dilutions, 278; high 
dilutions, 278; top-milk mixtures, 279, 287; whey mixtures, 
279 ; laboratory milk, 279, 280 
of infant feeding: Biedert, 94, 95; Heubner, 96; Henoch, 100; 
Baginsky, 100; Monti, 103; Filatow, 113; Marfan, 116; Ja- 
cobi, 119; Starr, 124; Holt, 128; Botch, 139; Ashby and 
Wright, 161; Cautley, 163; Fenwick, 165 
of milk analysis, 341, 342 
Michel, Charles, 234 
Milk commissions, 184, 185 
Milk-laboratory, 130, 143-147 
Miller, D. J. M., 174 
Miquel, 197 
Mixed feeding, 168 

milk, 45 
Monti, Alois, 35, 103, 176, 187 
Monti's Whey-Milk Mixture, 103, 105, 107 
Morse, J. L., 110 

Mother's milk: acidity, 104; amount secreted, 33; ash, 56; at dif- 
ferent times of lactation, 26, 30-33; bacteria in, 198, 200; before 
and after suckling, 39, 40; calories per litre, 32; casein, 23, 24, 
27; coagulation, 24, 68; colostrum, 20-22; composition, 22, 23, 
26-32, 34, 41; description, 18; effect of menstruation, 168, 169; 
effect of pregnancy, 168, 169; effect of infectious diseases, 168, 169; 
estimation of proteids, 14, 15, 19, 24-28, 30, 35; extractives, 25, 29; 
fat, 32, 35-37; fat-globules, 35, 36; in premature confinements, 
272; lecithin, 38, 39, 57, 58; mean composition, 41; nitrogen 
present, 32; nucleon, 38, 57, 58; phosphorus, 23, 38, 39, 43, 57; 
ratio of casein to albumin, 24, 27, 42; ratio of nitrogenous to non- 
nitrogenous substances, 33, 43; reaction, 20; salts, 37, 38, 57, 58; 
soluble albumin, 23, 24, 42; specific gravity, 18, 19, 31; sugar, 37; 
summary, 40-42; value of constituents, 269; variations in general 
composition, 27, 29-33 



364 INDEX. 

N 

Necessity for fat, 251, 252, 298 

for heat-producing food, 250 

for proteid, 251 

for salts, 253 

for sugar, 253 

for water, 10, 122, 176, 250, 257, 325 
Needs (alimentary) of infant at different ages, 262 
Nitrogen metabolism, 263, 264 
Northrup, 150 

o 

Oat jelly, 340 
Oatmeal-water, 337 
Overfeeding, 65 

P 

Palmer, George T., 193 
Panada, 9 

Pancreatic secretion, 66, 80 
Paracasein, 67, 68 
Paranuclein, 58, 69 
Parotid gland, 61, 62 
Pasteurization, 158, 217-220 

alterations produced by, 218 

cheap method of, 222, 223 

objections to, 223, 224 
Pepsin, 66, 75, 76 
Peptone, 66, 69, 76, 78, 88, 175 
Peptonized milk, 156, 162, 283, 284, 291, 332, 333, 339 

composition of, 335 
Percentage system, 128 
Peristalsis, 62, 77, 85, 86 
Peters, 191 
Pfeiffer, Emil, 26 

Phosphorus in metabolism, 255, 265, 289 
Plasmon, 324 

Premature infants, feeding of, 270-274 
milk modification for, 272, 274 
weight of, 273 
Preservatives, 195 
Principles of infant feeding, 275 



INDEX. 365 

Proprietary foods: analyses, 328; classification, 327; indications for 

use, 329, 330; use of, 166, 175, 317, 327 
Proteids, proper proportion of, 14, 15, 129, 154, 282-284 
Pseudonuclein, 69 
Ptyalin, 61, 80 
Pus in milk, 181, 182, 199, 200 

R 

Ratio of nitrogenous to non-nitrogenous elements in the diet, 116, 286 

Ravenel, 219 

Relative value of milk constituents, 257 

Rennet, 85 

Rennin, 84, 85 

experiments with, 85, 159 
Rice-water, 337 

Richmond, H. Droop, 29, 46, 257 
Rickets, 228, 229, 252 

phosphorus in, 59 
Rieth's Albumose Milk, 103, 110 
Rotch, T. M., 33, 34, 139, 187 
Rudisch, J., 175 
Rules for varying milk percentages, 135, 136, 323-325 



s 

Salge, 113 

Saliva, diastatic action of, 61, 62 

Salivary glands, 61, 62 

Salol test, 76 

Salts, 288 

Saunders, E. W., 331 

Schill, 197 

Schlesinger, 114 

Schlossmann, 31, 32, 106 

Schmid-Monnard, 115 

Schniirer, Joseph, 66 

Scraped meat, 172, 175, 340 

Scurvy, 59, 99, 118, 127, 227-229 

Sedgewick and Batchelder, 198 

Seifert, 100 

Separated milk, 59, 60 



366 INDEX. 

Skatol, 83, 88 
Skimmed milk, 59 
Smith, Theobald, 220 
Sodium carbonate, 107 

chloride, 123, 254, 289 
Soldner, 28 
Somatose, 175, 330 
Sonnenberger, 214 
Soxhlet, 224 
Spasmotoxin, 208 
Ssnitkin's rule, 142 
Standard milk, 184, 185 
Starch, 103, 171, 174, 289, 290 

digestion, 61, 62, 80, 141 

excess of, 120, 171 
Starchy diluents, 11, 129, 157, 159 
Starr, Louis, 124 
Steapsin, 80, 83 
Steffen's Veal Broth, 111 
Sterilization, 216, 217, 224, 226, 276, 293-295 

changes caused by, 225-227, 229-233 

destroys enzymes, 221 

fractional, 224 

in open vessels, 220 

objections to, 228 
Sterilized milk, dangers of, 205, 207, 216, 217, 232 

taste of, 59 
Stoklasa, 38 
Stomach, anatomy of the, 62, 77 

bacterial content of the, 76, 197 

capacity of the, 62-65, 143 

dilatation of the, 63, 65, 122 

time of evacuation of the, 62, 63, 115 
Stools, healthy, 86, 87 

number of, 86 

pathological, 93 
Storches' mucoid-proteid, 51 
Strippings, 50 
Submaxillary glands, 61 
Substitutes for milk, 160 
Sugar, proper proportion of, 129, 288 
Sugar solution, preparation of, 129, 297 



INDEX. 367 

T 

Tables of feeding: Feer, 97; Baginsky, 102; Starr, 125; Holt, 131; 

Rotch, 142, 149; Cautley, 163, 164; Fenwick, 165; authors', 322 
Taylor and Wells, 169, 187 
Thiemich and Papiewsky, 110 
Thomson, John, 166 
Thorner, 59 
Top milk, 287 

analyses, 132, 153, 158, 161, 310, 312-314 

mixtures, 133, 134, 158, 161, 310 
Townsend, C. W., 158 
Toxins in milk, 215 

Transmission of infectious diseases by milk, 182, 208, 209, 211 
Troitsky, 221 
Trypsin, 80, 81, 82 
Tubercular infection from cow's milk, 209 

from mother's milk, 209 
Tyrotoxicon, 208 

u 

Uffelmann, 87-89 
Urea elimination, 262 

V 

Variot, 226, 227 

Vegetables, 173 

Vigier's Humanized Milk, 105 

Voltmer's Mother's Milk, 103, 109 

Von Puteren, 197 

Von Ranke, 44 

Von Starck, 228 

Voorhees, Edward B., 194 

Voorhees, James D., 270 

w 

Warthin, A. S., 84 

Weaning, indications for, 167-169 

method of, 170 

time of, 167, 168 



368 INDEX. 

Weber, 205 

Wegscheider, 88 

Weight, 115, 152, 237, 259, 260 

charts, 244, 245, 248, 249 

gain in, 238-243, 293 

in mixed feeding, 241 

generalizing method, 244 

importance of recording, 249, 293 

individualizing method, 244 
Westcott, T. S., 154, 301 
Whey, 67, 162, 290 

analysis, 305, 336 

preparation of, 305, 336 
Whey-cream mixture, curdling of, 157 

mixtures, 155-157, 162, 290, 305 
White and Ladd, 156 
Whole milk, use of, 114, 118 
Winters, Joseph C, 153 
Wittmaack, 38 
Wolf and Friedjung, 73 
Woodward, George, 22 



Yeasts in cow's milk, 208 



THE END. 



MAY 3 1 1902 



MAY 3 



1C0PY DEL. TOLAT.DIY. 
MAY 31 1902 



, LIBRARY OF CONGRESS 

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